[Lord willing, I will further revise/expand this post in the future (feedback is appreciated). I’m posting it for now to provide context for the OPC Report on Republication.]
John Murray said he rejected the Covenant of Works for two reasons:
(1) The term is not felicitous, for the reason that the elements of grace entering into the administration are not properly provided for by the term ‘works’.
(2) It is not designated a covenant in Scripture. Hosea 6:7 may be interpreted otherwise and does not provide the basis for such a construction of the Adamic economy. Besides, Scripture always uses the term covenant, when applied to God’s administration to men, in reference to a provision that is redemptive or closely related to redemptive design. Covenant in Scripture denotes the oath-bound confirmation of promise and involves a security which the Adamic economy did not bestow.
Some have argued that John Murray did not reject the covenant of works. They insist that all the elements of the Covenant of Works are present in his view, he just chose not to use that language. This argument has plausibility with regards to Murray’s rejection of the term “covenant.” All one has to do is point out that he defined covenant wrong. He still held to all the elements of a covenant with Adam when covenant is properly defined.
However, most tend to overlook the much more important reason Murray had for rejecting the Covenant of Works. Murray explicitly argued that the reward of eternal life would not have been by works. It would have been a gift of God’s grace, not a reward of debt according to justice. What Murray was rejecting was the concept of ex pacto or covenantal merit, known as “the works principle.” Thus, while one could argue he held to an Adamic Covenant (by rejecting Murray’s definition of covenant), he did not hold to an Adamic Covenant of Works.
Part of his argument is that there is no works principle found anywhere in Scripture – pre or post-fall. “In connection with the promise of life it does not appear justifiable to appeal, as frequently has been done, to the principle enunciated in certain texts (cf. Lev. 18:5; Rom. 10:5; Gal. 3:12), ‘This do and thou shalt live’.”
In a paper on confessional subscription, J.V. Fesko says
Murray did not accept the Standards’ teaching regarding the Covenant of Works… Murray did not believe that he held to the common Reformed position that was historically advocated by Reformed theologians or by the Westminster Standards. In fact, he saw himself as a self-avowed revisionist on the subject of covenant theology…
What led Murray to reject the Covenant of Works?
Many focus on the rise of dispensationalism and Murray’s response to it as an explanation for his rejection of the Covenant of Works. In other words, he just over-reacted to dispensationalism by flattening out all of Scripture.
However, Murray actually said he was influenced by Karl Barth on this point. Ligon Duncan explains:
Now, here is the inside scoop. As Donald Macleod talked with John Murray when he came back from Scotland, there were a number of things that had made a major impact on Murray with regard to Covenant Theology. For one thing, Murray was impacted by Vos and by a guy named Adolph Desmond. Desmond was a big time German New Testament scholar at the turn of the twentieth century who had argued very strongly that Covenant should not be translated as a contract or a treaty or a mutual relationship, but it ought to be translated as a disposition or a testament, something that was one-sided as opposed to two-sided. And Desmond did this because he had uncovered all this literature from Greek legal documents contemporary to the New Testament and many New Testament scholars followed Desmond for a period of time. His views have since then been overturned, but he was very influential in the first part of the twentieth century. And so Murray was very influenced by this one-sided idea of covenant. And he found the obediential aspect of the historic Covenant of Works to be a little two-sided for his taste. So, you will see him, when he defines covenant in his little tract called The Covenant of Grace, he will define it in a very one-sided, a very monopluric sort of way. And he is following Vos there and he is following Desmond.
But, the other interesting thing is, is that Murray indicated to Macleod that he had actually been impacted a bit by Barth’s argumentation on the nature of the Covenant of Works and so although Murray would have been stridently in opposition to Barth’s doctrine of the Scripture and his doctrine of the Atonement, yet he was swayed to a certain extent by some of Barth’s arguments regarding Covenant of Works. And Macleod had opportunity to interact with him on that and argue against those particular points, but Murray held to his objections and to this day, Westminster Seminary has tended to be a little bit skittish about the Covenant of Works and the Covenant of Grace framework.
Covenant of Works and Covenant of Grace (lecture)
Cornelis P. Venema elaborates in a journal article titled Recent Criticisms of the Covenant of Works in the Westminster Confession of Faith.
Murray, though a faithful exponent of the system of doctrine contained in the WCF, was perhaps more critical of this aspect of the WCF than he was of any other. Based upon his own biblical-theological reflection, Murray offered several of what he believed were needed correctives to the traditional formulations of federal theology, including the classical form found in the WCF…
There are several respects in which Murray’s treatment of this Adamic administration differs from traditional covenant theology. As we have already noted, this difference is partially terminological… But the divergence is far more than terminological…
This promise [of eternal life] would not be granted upon the principle of strict justice or merit — God’s justice does not require that Adam should ever be granted the status of immutability in fellowship with God — but would be expression of God’s undeserved favor…
[In connection with the promise of life it does not appear justifiable to appeal, as frequently has been done, to the principle enunciated in certain texts (cf. Lev. 18:5; Rom. 10:5; Gal. 3:12), ‘This do and thou shalt live’. The principle asserted in these texts is the principle of equity, that righteousness is always followed by the corresponding award. From the promise of the Adamic administration we must dissociate all notions of meritorious reward. The promise of confirmed integrity and blessedness was one annexed to an obedience that Adam owed and, therefore, was a promise of grace. All that Adam could have claimed on the basis of equity was justification and life as long as he perfectly obeyed, but not confirmation so as to insure indefectibility. Adam could claim the fulfilment of the promise if he stood the probation, but only on the basis of God’s faithfulness, not on the basis of justice.]
Murray also challenged another commonplace of the older federal theology, namely, that the Mosaic economy or covenant included within itself a repetition of the obligation of obedience, first enunciated in the covenant of works.
The view that in the Mosaic covenant there was a repetition of the so-called covenant of works, current among covenant theologians, is a grave misconception and involves an erroneous construction of the Mosaic covenant, as well as fails to assess the uniqueness of the Adamic administration. The Mosaic covenant was distinctly redemptive in character and was continuous with and extensive of the Abrahamic covenants.
Apparently, because Murray wants to emphasize the gracious and sovereign disposition of the Adamic arrangement, as well as the essential graciousness of the biblical covenant of grace, he does not want to admit the legal requirement of obedience to be as integral to this arrangement or the post-fall covenant of grace, as was typically the case in the history of covenant theology.
Venema goes on to argue that WCF 7.1, which describes God’s voluntary condescension in the creation of the Covenant of Works, satisfactorily answers Murray’s concerns about the gracious nature of the promise of eternal life.
This emphasis upon all of God’s covenants as voluntary condescensions preserves, it seems to me, the WCF from the charge of depriving the original covenant of the element of God’s favor and goodness, as though it were only a matter of strict justice between a Master and his servant. Moreover, by its apparent distinction between the original natural state in which “reasonable creatures do owe obedience unto him [God] as their Creator” and the covenant of works, the WCF preserves the element of unmerited bestowal and grant in this original covenant. It simply cannot be argued convincingly that the WCF neglects this component of the original covenant relationship between God and the creature before the fall into sin and the institution of the covenant of grace.
But if WCF 7.1 easily addresses Murray’s concern, why did Murray still have a concern? Did he not understand 7.1? That’s possible – after all, Van Til certainly caused some confusion. But I don’t think that was the case with Murray. As the chair of systematic theology and one acquainted with historical theology, I doubt Murray was oblivious to something that was obvious to Venema.
In fact, I think it was actually Murray’s acquaintance with the confession and his systematic concern that motivated his revision. I think Murray recognized that the Westminster Confession is self-contradictory on this point and he sought to iron it out.
If you recall Murray’s quote above about the works principle, he mentions Lev 18:5, Gal 3:12, Rom 10:5 as the texts frequently appealed to to articulate the works principle of the Covenant of Works. The WCF cites Gal 3:12 and Rom 10:5 as proof of the covenant of works (in the catechism as well). However, it does not quote Lev 18:5. Why not? Well, because Leviticus 18:5 states the terms of the Mosaic Covenant, which the Westminster Confession says is the Covenant of Grace. Therefore Leviticus 18:5 cannot be a statement of the terms of the Covenant of Works.
In a very helpful WTJ essay titled In Defense of Moses, D. Patrick Ramsey explains why Leviticus 18:5 was not included in the Standards as a proof-text for the Covenant of Works.
Objection 4: In expounding the covenant of works made with Adam the Westminster Confession of Faith uses Rom 10:5 and Gal 3:12 as proof texts. Both of these texts quote Lev 18:5, which refers to the Mosaic Covenant. Therefore, the Divines understood the Mosaic Covenant to be a covenant of works.
The texts that the Westminster Standards used to expound the Covenant of Works are Gen 1:26-27; 2:17; Job 28:28; Eccl 7:29; Rom 2:14-15; 5:12-20; 10:5; Gal 3:10; 3:12 (WCF 7.2; 19.1). None of these texts are from the Mosaic Covenant; however, Rom 10:5 and Gal 3:10, 12 quote verses from the Mosaic Covenant.
The reasons for appealing to these New Testament quotations of Moses vary among the writings of the Puritans.  Some believed that they taught that the Covenant of Works was renewed at Mount Sinai though with evangelical purposes and intentions…  A similar position stated that these passages taught that the Mosaic Law contained a restatement of the principle of works. It was not re-established or renewed, only republished and repeated in order to drive men to Christ…
 A third Puritan position understood the proof texts used by the Westminster Confession of Faith to refer to the Law absolutely or separated from the Gospel. When the Mosaic Law is taken out of its context, then and only then does it become contrary to the Gospel by becoming the matter (describes the righteousness required in the Covenant of Works) and/or form (offers life by works) of the Covenant of Works. Hence, passages like Deut 27:26 and Lev 18:5 did not, in their original intent, renew or repeat the Covenant of Works.
The Pharisees and Judaizers of Paul’s day distorted the Law by separating it from the Gospel and used it for their justification before God. Paul’s quotations of Moses in Romans and Galatians are thus referring to the Jews’ perversion of the Law. In so doing the apostle expounds the principle of works, which is applicable to the Covenant of Works made with Adam.
Of these three possible explanations for the use of Gal 3:10, 12 and Rom 10:5 as proof texts for the Covenant of Works, the third is the most likely. This is so because the Divines did not use Lev 18:5, Deut 27:26, or any passage pertaining to the Mosaic Covenant as proof texts. If they had understood the Mosaic Covenant to be a renewal or republication of the Covenant of Works, they probably would have appealed to the Law of Moses directly, as many Puritans did.
So, according to this view, the moral law itself, separated from the Gospel, contains the works principle. In it’s original context, Leviticus 18:5 is a statement of the moral law in the Covenant of Grace. But in quoting Leviticus 18:5, Paul abstracts the law from it’s context in the Mosaic Covenant of Grace and applies it to his situation with the Judaizers. Guy P. Waters, in his chapter in The Law is Not of Faith titled Romans 10:5 and the Covenant of Works? argues this point.
Paul considers the moral demands of the Mosaic law, in distinction from the gracious covenant in which they were formally promulgated, to set forth the standard of righteousness required by the covenant of works.
 This position for which I will be arguing is essentially that argued by Anthony Burgess, “The Law (as to this purpose) may be considered more largely, as that whole doctrine delivered on Mount Sinai, with the preface and promises adjoyned, and all things that may be reduced to it; or more strictly, as it is an abstracted rule of righteousnesse, holding forth life upon no termes, but perfect obedience. Now take it in the former sense, it was a Covenant of grace; take it in the later sense, as abstracted from Moses his administration of it, and so it was not of grace, but workes,” Vindiciae Legis: Or, A Vindication of the Morall Law and the Covenants, from the Errours of
Papists, Arminians, Socinians, and more especially, Antinomians. In XXX. Lectures, preached at Laurence-Jury, London (2d ed.; London, 1647), 235. Anthony Burgess was a member of the Westminster Assembly and served on the committee that drafted WCF 19 (“Of the Law of God”).
Waters actually quotes from Murray’s Appendix B “Leviticus 18:5” from his Romans commentary at this point, demonstrating Murray has accurately pinpointed a crucial question.
John Murray observes that “[The problem that arises from this use of Lev. 18:5 is that the latter text does not appear in a context that deals with legal righteousness as opposed to that of faith.] Lev. 18:5 is in a context in which the claims of God upon his redeemed and covenant people are being asserted and urged upon Israel… [It] refers not to the life accruing from doing in a legalistic framework but to the blessing attendant upon obedience in a redemptive and covenant relationship to God.” If the Scripture teaches that the Mosaic administration is an administration of the covenant of grace, as the Westminster divines affirm (7.5), then how could Paul have interpreted Lev 18:5 as he has? How could he have taken a passage which, in context, appears to refer to the sanctificational works of a redeemed person within the covenant community, and apply this text to individuals seeking the righteousness of justification on the basis of their performance?… Has Paul misquoted Leviticus 18:5 at Romans 10:5?
Waters’ proposed solution is that the moral law itself inherently includes the works principle (ex pacto merit) unless the works principle is stripped away by coming to us through the hand of Christ, as it did in the Mosaic Covenant. As I demonstrated in another post, the problem with this view is that it contradicts WCF 7.1, which teaches that the law itself does not offer any reward for obedience to the law and therefore does not include any works principle. The works principle is only added to the law in the Covenant of Works.
Murray was sharper than Waters on this point. I believe he recognized that Waters’ solution (repeating a historic solution) was no solution at all because it was self-contradictory in that it conflated the law and the covenant of works on this point while elsewhere necessarily distinguishing them (see the Waters post).
Commenting on Romans 10:5, Murray says that “’The man that doeth the righteousness of the law shall live thereby”, is, of itself, an adequate and watertight definition of the principle of legalism. (See Appendix B, pp. 249ff., for fuller discussion.)” In Appendix B: Leviticus 18:5 he argues that this principle is “the principle of equity in God’s government” and there are “three distinct relationships in which [it] has relevance.”
1… Wherever there is righteousness to the full extent of God’s demand there must also be the corresponding justification and life… God’s judgment is always according to truth. Perfect righteousness must elicit God’s favour or complacency and with this favour is the life that is commensurate with it. This would have obtained for Adam in sinless integrity apart from any special constitution that special grace would have contemplated.
Note well: this principle applied to Adam prior to and apart from God’s condescension to reward his obedience – that is, prior to and apart from any Covenant of Works. Recall what Murray said in his Adamic Administration essay. “All that Adam could have claimed on the basis of equity was justification and life as long as he perfectly obeyed, but not confirmation so as to insure indefectibility.” In other words, “life” according to this principle is not “eternal life” but merely “not death.”
2. The principle ‘the man who does shall live’ must be regarded as totally inoperative within the realm of sin… In alluding to Lev. 18:5 at this point he uses the formula ‘the man that doeth… shall live thereby’ as a proper expression in itself of the principle of works-righteousness in contrast with the righteousness of faith. We have no right to contest the apostle’s right to use the terms of Lev. 18:5 for this purpose since they do describe that which holds true when law-righteousness is operative unto justification and life and also express the conception entertained by the person who espouses the same as the way of acceptance with God (cf. also Gal. 3:12).
In other words, the second relationship is in reference to the first, but at a time when man has already fallen. It is a hypothetical statement of what is true if man had not fallen, but that is now “totally inoperative within the realm of sin.” This is how Paul uses it in Romans 10:5. He is adopting “the conception entertained by the person who espouses” righteousness by the law.
3… righteousness and life are never separable. Within the realm of justification by grace through faith there is not only acceptance with God as righteous in the righteousness of Christ but there is also the new life which the believer lives… So Paul can say in the most absolute terms, ‘If ye live after the flesh, ye must die; but if by the Spirit ye put to death the deeds of the body, ye shall live” (8:13). In the realm of grace, therefore, obedience is the way of life. He that does the commandments of God lives in them. The fruit of the Spirit is well-pleasing to God… It is this principle that appears in Lev. 18:5…
Lev. 18:1-5 is parallel to Exod. 20:1-17; Deut 5:6-21… The whole passage is no more “legalistic” than are the ten commandments. Hence the words “which if a man do, he shall live in them” (vs. 5) refers not to the life accruing from doing in a legalistic framework but to the blessing attendant upon obedience in a redemptive and covenant relationship to God.
Note the difference between Murray and Waters. Waters says Paul can quote Leviticus 18:5 on this point because the moral demands of the law itself set forth the works principle found in the Covenant of Works. When the gracious covenant context is added to the law, this works principle is removed. Waters notes that WCF 7.2 references Romans 10:5. Murray rejects the confession on this point arguing there is no works principle and no Covenant of Works.
The problem with Murray’s attempted explanation is that it does not sufficiently explain how Paul can quote Leviticus 18:5 as expressing law righteousness since it, in fact, does not. Paul does not say “according to a mistaken conception entertained by the person who espouses a law righteousness that no longer applies, the person who does the commandments shall live by them.” Rather, Paul says “Moses writes about the righteousness that is based on the law, that the person who does the commandments shall live by them.” If Leviticus 18:5 “refers not to the life accuring from doing in a legalistic framework” then Moses did not “write about the righteousness that is based on the law.” Paul did not merely “allude” to Leviticus 18:5, nor did he merely “use the terms of Lev. 18:5.” Paul quoted Moses’ teaching on law-righteousness.
When the OPC was formed, it established a Committee on Texts and Proof Texts, headed by John Murray.
As a preliminary step toward the printing of the doctrinal standards of the Orthodox Presbyterian Church, the Seventh General Assembly (1940) established a Committee on Texts and Proof Texts (consisting of John Murray [chairman], E. J. Young, and Ned B. Stonehouse, who was replaced in 1941 by John H. Skilton) to study the texts and proof texts of those documents. That Committee submitted to the Eighteenth General Assembly (1951) “the text of the Confession of Faith, together with the proof texts as revised by the Committee.” The text, except for the revisions that had been adopted by the Second General Assembly in 1936, was “derived from the original manuscript written by Cornelius Burges in 1646, edited by S. W. Carruthers [in 1937] and published by the Presbyterian Church of England in 1946.” That text of the Confession, with a few corrections, was adopted by the Twentysecond General Assembly (1955), approved by nearly all the presbyteries, and adopted again by the Twenty-third General Assembly (1956). The proof texts prepared by the Committee were accepted for publication. The Confession was then published with these proof texts (as citations, not full texts) by the Committee on Christian Education and reprinted by Great Commission Publications
The Scripture proof texts were originally prepared by the Westminster divines, revised over the years by a succession of committees, and approved for publication by various general assemblies of the OPC, but are not a part of the constitution itself.
The original Westminster Confession did not cite Leviticus 18:5 anywhere. In light of the resolution that Murray arrived at, he added Lev 18:5 as a proof text to WCF 19.6.
VI. Although true believers be not under the law, as a covenant of works, to be thereby justified, or condemned;[a] yet is it of great use to them, as well as to others; in that, as a rule of life informing them of the will of God, and their duty, it directs, and binds them to walk accordingly; discovering also the sinful pollutions of their nature, hearts, and lives;[c] so as, examining themselves thereby, they may come to further conviction of, humiliation for, and hatred against sin; together with a clearer sight of the need they have of Christ, and the perfection of His obedience. It is likewise of use to the regenerate, to restrain their corruptions, in that it forbids sin: and the threatenings of it serve to show what even their sins deserve; and what afflictions, in this life, they may expect for them, although freed from the curse thereof threatened in the law. The promises of it, in like manner, show them God’s approbation of obedience, and what blessings they may expect upon the performance thereof;[s] although not as due to them by the law, as a covenant of works. So as, a man’s doing good, and refraining from evil, because the law encourageth to the one and deterreth from the other, is no evidence of his being under the law; and not under grace.
s. Ex. 19:5–6. Now therefore, if ye will obey my voice indeed, and keep my covenant, then ye shall be a peculiar treasure unto me above all people: for all the earth is mine: and ye shall be unto me a kingdom of priests, and an holy nation. These are the words which thou shalt speak unto the children of Israel. Deut. 5:33. Ye shall walk in all the ways which the Lord your God hath commanded you, that ye may live, and that it may be well with you, and that ye may prolong your days in the land which ye shall possess. Lev. 18:5. Ye shall therefore keep my statutes, and my judgments: which if a man do, he shall live in them: I am the Lord. Matt. 19:17. And he said unto him, Why callest thou me good? there is none good but one, that is, God: but if thou wilt enter into life, keep the commandments. Lev. 26:1–13. … If ye walk in my statutes, and keep my commandments, and do them; then I will give you rain in due season, and the land shall yield her increase, and the trees of the field shall yield their fruit. And your threshing shall reach unto the vintage, and the vintage shall reach unto the sowing time: and ye shall eat your bread to the full, and dwell in your land safely. And I will give peace in the land, and ye shall lie down, and none shall make you afraid: and I will rid evil beasts out of the land, neither shall the sword go through your land. And ye shall chase your enemies, and they shall fall before you by the sword.… For I will have respect unto you, and make you fruitful, and multiply you, and establish my covenant with you.… And I will walk among you, and will be your God, and ye shall be my people.… 2 Cor. 6:16. And what agreement hath the temple of God with idols? for ye are the temple of the living God; as God hath said, I will dwell in them, and walk in them; and I will be their God, and they shall be my people. Eph. 6:2–3. Honour thy father and mother; (which is the first commandment with promise;) that it may be well with thee, and thou mayest live long on the earth. Ps. 19:11. Moreover by them is thy servant warned: and in keeping of them there is great reward. Ps. 37:11. But the meek shall inherit the earth; and shall delight themselves in the abundance of peace. Matt. 5:5. Blessed are the meek: for they shall inherit the earth.
Judgment According to Works
Note that Matthew 19:17 was added as well. This raises an interesting question as to how Murray saw this principle in relation to “life” and the final judgment for the redeemed Christian. In a lecture titled “Justification” contained in his Collected Writings, Murray says
While it makes void the gospel to introduce works in connection with justification, nevertheless works done in faith, from the motive of love to God, in obedience to the revealed will of God and to the end of his glory are intrinsically good and acceptable to God. As such they will be the criterion of reward in the life to come. This is apparent from such passages as Matthew 10:41; 1 Corinthians 3:8–9, 11–15; 4:5; 2 Corinthians 5:10; 2 Timothy 4:7. We must maintain therefore, justification complete and irrevocable by grace through faith and apart from works, and at the same time, future reward according to works. In reference to these two doctrines it is important to observe the following:
(i) This future reward is not justification and contributes nothing to that which constitutes justification. (ii) This future reward is not salvation. Salvation is by grace and it is not as a reward for works that we are saved. (iii) The reward has reference to the degree of glory bestowed in the state of bliss, that is, the station a person is to occupy in glory and does not have reference to the gift of glory itself. (iv) This reward is not administered because good works earn or merit reward, but because God is graciously pleased to reward them. That is to say it is a reward of grace. (In the Romish scheme good works have real merit and constitute the ground of the title to everlasting life.) The good works are rewarded because they are intrinsically good and well-pleasing to God. They are not rewarded because they earn reward but they are rewarded only as labour, work or service that is the fruit of God’s grace, conformed to his will and therefore intrinsically good and well-pleasing to him. They could not even be rewarded of grace if they were principally and intrinsically evil.
He held that there was a future judgment for God’s redeemed people, but only to determine the degree of reward they will receive in glory, not whether they will enter glory. However, as we just saw, Matthew 19:17 was cited in order to explain “what blessings [Christians] may expect upon the performance” of the law. Matthew 19:17 is Jesus’ answer to the rich young man who asked “Teacher, what good deed must I do to have eternal life?” – that is, to enter glory, as Jesus replied “If you would enter life, keep the commandments.” Thus there appears to be a bit of tension in Murray’s thought on this point. Note his commentary on Romans 2:5-16 where he rejects the hypothetical view held by older reformed theologians.
The reward of this aspiration is in like manner the eschatology of the believer, “eternal life”… Could God judge any unto the reward of eternal life (cf. vs. 7) if works are the criteria? ‘The apostle thus speaks, not in the way of abstract hypothesis but of concrete assertion… He says not what God would do were He to proceed in accordance with the primal rule and standard of the law, but what, proceeding according to that rule, He will actually do.’… The determining factor in the rewards of retribution or of glory is not the privileged position of the Jew but evil-doing or well-doing respectively.
Samuel Waldron notes
Murray’s lecture on justification contained in the Collected Writings affirms that works only have to do with the degree of reward in glory, while in his Romans commentary he affirms that the judgment by works which has the twin consequences of eternal life and wrath is not hypothetical. I see no way to evade the fact of some contradiction between the two statements…
I think a good argument could be made that the Romans commentary contains Murray’s more mature and definitive thoughts. This is so for two reasons. First, as Iain Murray notes in his introduction to CW 2 (vi-ix) Murray resisted appeals to publish the class lectures from which the article on justification in CW 2 is taken. It seems clear, then, that his commentary which he wrote for publication should be given some precedence over the lecture in CW 2. Also the commentary was published in 1959 only 7 years before his retirement from Westminster in 1966. The lecture likely dates from much earlier in his tenure at Westminster where he taught systematic theology from 1930.
So there appears to be development in Murray’s thought as he works out the implications of Leviticus 18:5. Returning to his commentary, note that verse 13 goes on to say “the doers of the law who will be justified,” which leads Murray directly towards a dangerous position. He attempts to put on the brakes
It is quite unnecessary to find in this verse any doctrine of justification by works in conflict with the teaching of this epistle in later chapters. Whether any will be actually justified by works either in this life or at the final judgment is beside the apostle’s interest and design at this juncture. The burden of this verse is that not the hearers or mere possessors of the law will be justified before God but that in terms of the law the criterion is doing, not hearing. The apostle’s appeal to this principle serves that purpose truly and effectively, and there is no need to import questions that are not relevant to the universe of discourse.
This is the first occasion that the word “justify” is used in this epistle. Although it is not used here with reference to the justification which is the grand theme of the epistle, the forensic meaning of the term is evident even in this case. “Shall be justified” is synonymous with “just before God” and the latter refers to standing or status in the sight of God. To justify, therefore, would be the action whereby men would be recognized as just before God or the action whereby men are given the status of being just in God’s sight. For a fuller treatment of the nature of justification and the meaning of the terms the reader is referred to the appendix on this subject (pp. 336 ff).
Murray attempts to backpedal by arguing that “will be justified” is hypothetical, in direct contradiction to his previous statements about the passage. As a result, you will actually get two different interpretations of Murray, some saying he denied the hypothetical interpretation, others saying he agreed with it. (See here and here as examples)
In an attempt to work out the contradictions in the system of theology found in the Westminster Confession, particularly the idea that the Mosaic Covenant of Works was the Covenant of Grace, John Murray rejected the Covenant of Works on the grounds that Scripture does not teach a “works principle” in Leviticus 18:5 or anywhere else. Contrary to Guy Waters and others, Murray recognized that Leviticus 18:5 was the statement of a principle – the principle of equity – not simply the law itself. He therefore recognized that the principle found in Leviticus 18:5 and Romans 10:5 and Galatians 3:12 must be the same. He recognized that if the principle found in Leviticus 18:5 is part of the terms of the Covenant of Grace, then that principle is not part of the terms of a Covenant of Works. Therefore the principle found in Romans 10:5 and Galatians 3:12 is not a Covenant of Works. Therefore Scripture does not teach a Covenant of Works.
As Murray began to iron out Westminster’s inconsistent appeal to Romans 10:5 and Galatians 3:12, he also began to iron out the implications of his view for the rest of his theology. We saw progression in his thought in the wrong direction – towards a false gospel of justification by works. He slammed on the breaks, but without a consistent explanation as to why – leaving it to his successors to work out.