The interpretation timeline
Galatians 3:21 Douay-Rheims

Was the law then against the promises of God? God forbid. For if there had been a law given which could give life, verily justice should have been by the law.

A.D. 407 – 1871 6 witnesses

Patristic

before A.D. 750
407
A.D.
John Chrysostom Patristic
A.D. 347–407
“For if the blessing is given in the seed of Abraham, but the Law brings in the curse, it must be contrary to the promises. This objection he meets, first, by a protest, in the words, "God forbid:" And next he brings his proof; "For if there had been a law given which could make alive. verily righteousness would have been of the Law." His meaning is as follows; If we had our hope of life in the Law, and our salvation depended on it, the objection might be valid. But if it save you, by means of Faith, though it brings you under the curse, you suffer nothing from it, gain no harm, in that Faith comes and sets all right. Had the promise been by the Law, you had reasonably feared lest, separating from the Law, you should separate from righteousness, but if it was given in order to shut up all, that is, to convince all and expose their individual sins, far from excluding you from the promises, it now aids you in obtaining them. This is shown by the words...”
Source

Scholastic

c. 1100 – 1500
1273
A.D.
Thomas Aquinas Catholic
1225–1274
“Here the Apostle raises another doubt, namely whether the law is harmful to grace. And first he raises the doubt, saying "Is the law then," etc., as if to say: if the law was established on account of transgressions, does the law then act against the promises of God — namely, so that what God promised he would do through the promised seed, he does through something else? God forbid. As if to say: no. For above, in the same place: "the law does not make void the covenant so as to nullify the promises," etc. Romans 7:12: "the law is holy, and the commandment holy." Second, when he says "For if a law had been given," etc., he resolves the doubt. And first he shows that the law is not against the promises of God; second, that it is in service of the promises, at the point "but concluded," etc. He says, therefore, that although the law was established on account of transgressions, it is nevertheless not contrary to the promise of God, because it cannot remove the transgressions themselves. For if it did remove them, then it would clearly be against the promises of God, because justice would be through another way than the one God promised — since it would be through the law and not through faith — whereas nevertheless it is said, Habakkuk 2:4: "my just one lives from faith." Romans 3:22: "the justice of God is through the faith of Jesus Christ." And therefore he says that if a law had been given of such a kind that it could give life — that is, were of such power that it could confer the life of grace and eternal blessedness — then truly, and not merely apparently, justice would be from the law, if the law did what faith is said to do; and thus faith would be in vain. But the law does not justify, because the letter — namely, of the law — kills, as is said in 2 Corinthians 3:6, and Romans 8:2: "for the law of the spirit of life in Christ Jesus," etc. Then when he says "but Scripture concluded," etc., he shows that the law not only is not contrary to grace but is even in service to it. And first he shows that the law serves the promises of God; second, how this service was made manifest among the Jews, at the point "but before faith came," etc.; third, how the Gentiles too, without the law, obtained the promises of God, at the point "for you are all sons of God," etc. Concerning the first, it must be known that the law serves the promises of God in general with respect to two things. First, because it manifests sins. Romans 3:20: "through the law, knowledge of sin." Then, because it manifests human weakness, inasmuch as man cannot avoid sin except through grace, which was not given through the law. And just as these two things — namely, knowledge of the disease and the powerlessness of the sick person — greatly induce one to seek a physician, so knowledge of sin and of one's own powerlessness induce one to seek Christ. Thus, then, the law served grace, insofar as it supplied knowledge of sin and experience of one's own powerlessness. And therefore he says "Scripture" — that is, the written law — "concluded," that is, it held the Jews shut in, "under sin" — that is, it showed them the sins that they were committing. Romans 7:7: "I did not know concupiscence," etc. Likewise it "concluded," because with the law coming they took occasion for sin. Romans 11:32: "God has concluded all things under unbelief," etc. And this was so that man might seek grace. And therefore he says "that the promise" — that is, the grace that had been promised — "might be given not only to the Jews, but to all believers," because that grace was able to free from sins, and this grace is from the faith of Jesus Christ. Then when he says "but before it came," etc., he sets forth the experience of this service made manifest among the Jews. And first he sets forth the service rendered to the Jews; second, he draws a certain corollary, at the point "therefore the law was our pedagogue," etc. He says, therefore: if Scripture — that is, the written law — held all things shut in under sin, what benefits did the Jews have from the law before faith came from grace? He answers and says: we Jews, before the coming of faith, were kept under the law, inasmuch as it made us avoid idolatry and many other evils; we were kept, I say, not as free men, but as it were as servants under fear, and this "under the law" — that is, under the burden and dominion of the law. Romans 7:1: "the law has dominion over a man for as long as he lives," etc. And we were kept "shut in" — that is, preserved lest we should slip away from life, but were being prepared for it — that is, for that so-good faith which was to be revealed. Isaiah 56:1: "my salvation is near, that it may come, and my justice, that it may be revealed." And he says "to be revealed," because since faith exceeds every human intellect, it cannot be had through one's own understanding, but from revelation and the gift of God. Isaiah 40:5: "the glory of the Lord shall be revealed," etc. Or: for that faith which was to be revealed in the time of grace, lying hidden in ancient times under many signs. Whence also, at the time of Christ, the veil of the temple was torn, Matthew 27:51. Consequently, when he says "the law was our pedagogue," etc., he draws a certain corollary. And first he shows the office of the law; second, the attestation of that office, at the point "but when the fullness of time came," etc. Now the office of the law was the office of a pedagogue, and therefore he says "the law was our pedagogue," etc. For as long as an heir cannot obtain the benefit of the inheritance, whether on account of a deficiency of age or of some due perfection, he is kept and guarded by some instructor, and this instructor indeed is called a "pedagogue," from "paidos," which means "boy," and "agoge," which means "leading." For through the law the Jews, like weak children, were held back from evil through fear of punishment, and were advanced toward the good by the love and promise of temporal things. Now to the Jews was promised the blessing of the future seed with a view to obtaining the inheritance, but the time of obtaining that inheritance itself had not yet come. And therefore it was necessary that they be preserved until the time of the future seed, and be restrained from unlawful things — which was accomplished through the law. And therefore he says "therefore," etc., as if to say: since we were kept under the law, the law was our pedagogue — that is, directing and preserving us "in Christ," that is, in the way of Christ. And this was so that we might be justified from the faith of Christ. Hosea 11:1: "Israel a child, and I loved him." Jeremiah 31:18: "you have chastised me, Lord, and I was instructed," etc. Romans 3:28: "for we reckon that a man is justified through faith," etc. And although the law was our pedagogue, it nevertheless did not lead to the perfect inheritance, because, as is said in Hebrews 7: "the law brought no one to perfection," etc. But this office ceased after faith came. And this is what he says: "but when faith came" — namely, the faith of Christ — "we are now no longer under a pedagogue" — that is, under a coercion which is not necessary for free men. 1 Corinthians 15: "when I was a child," etc.; "but when I became a man," etc. 2 Corinthians 5:17: "if then any new creature in Christ, the old things have passed away," etc.”

Reformation

c. 1500 – 1650
1637
A.D.
1567–1637
“Is the law then against the promises of God l Jerome correctly points out that this is an answer by anticipation to the objection to which S. Paul had exposed himself in verse 19, when he said, “ The law was added because of transgressions till the seed should come.” For any one might say : If the law was added to the promise, and, as it were, removed it, it seems to have taken to itself the office of quickening and justifying men, so that it may be regarded as doing the work of the promise till Christ should come ; for if not, why was it added, unless it were, as you say youi> self, because of transgressions , to destroy them by the living and virtuous actions prescribed by the law for Justification? If this be so, then the law is against the promises of God, for God promised this justification to faith in Christ, not to the law, nay. He thereby excluded it from the law. That S. Paul is meeting an objection of this sort is obvious from what follows. The law, he exclaims, cannot give life; therefore, it 280 THE EPISTLE TO THE is not against the promises of God which offer that spiritual life in Christ. The antecedent is proved thus : If the law could give life it could also justify; but this it cannot do (ver. 22). Hence the law was only given to be our paedagogue to Christ, to lead as to justification by faith. Or it may be put thus : When I said that the law was given because of transgressions, I meant that its function was to prevent them by fear of punishment, that passion might not issue in action ; I did not mean that the law alone could calm the violence of passion within, or give that grace by which we fulfil the law. God forbid. It is impossible that God should give a law contra* dictory to His promises, for this would be for God to contradict Himself. The law which came after was not opposed to the preceding promises, but its office was to admonish men to prepare themselves worthily for Christ and His GospeL Therefore the law is not contrary to the promise, but establishes it For if there had been a law given which could have given life. To give life is to impart righteousness to the soul. But, as S. Paul appears to distinguish between life and righteousness , it is better to say that to give life stands for to quicken man's works . This is done when a man does virtuous actions out of the spirit of charity. The argument is from the effect to the cause, from a living work to life ; as we say : This man eats, talks, moves, therefore he is alive. In the same way, if the law could produce in us living works, it could also give us the spirit of charity from which they spring, for the works of the Spirit presuppose the Spirit, just as motion does life”
Source

Post-Reformation

c. 1650 – 1900
1771
A.D.
John Gill Reformed
1697–1771
“Is the law then against the promises of God?.... If the law was added because of transgressions, and curses for them, and if the inheritance is not of it, but by promise, were it, it would not be by promise, then, says an objector, it is against the promises: these are contrary to one another, and God, in giving the one and the other, must contradict himself: to which it is replied, God forbid; a way of speaking the apostle uses, when he would express his abhorrence and detestation of anything, as here; for though the law and promises are distinct things, and have their separate uses, yet they are not contradictory to each other; the law has its use, and so have the promises; the promises do not set aside the law as useless on all accounts, nor does the law disannul the promises, but is subservient to them: for if there had been a law which could have given life, verily righteousness should have been by the law; but the law cannot give life, spiritual life to a dead sinner; God only can do this, Father, Son, and Spirit; so far is the law from giving it efficiently, that it is not so much as the means of it; it is not made use of this way; God makes use of the law to kill, but not to make alive; he makes use of the law to strike dead all a man's hopes of happiness, by the deeds of it; but it is the Gospel he uses to quicken and comfort; that is the Spirit that giveth life. The law requires as much of a dead sinner, as it did of Adam in innocence, but gives him no life, activity, and strength to perform; could it quicken him, and enable him to do all its demands perfectly, then there would be righteousness, and so justification by it, as by the promise; whence it appears that there is no contrariety in the law to the promises: the reason why there is no righteousness is, because it cannot give life, spiritual life and strength; and if so, then not eternal life; which is the free gift of God, and not the merit of men's works: this is directly contrary to a notion of the Jews, who cry up the law as a life giving law; say they (n), "great is the law, , "for it giveth life to them that do it", in this world, and in the world to come:'' and elsewhere (o), "the law is a tree of life to all that study in it, , "to give unto them life" in this world, and "to give unto them life" in the world to come.'' (n) Pirke Abot, c. 6. sect. 6. (o) Zohar in Gen. fol. 70. 3. & in Num. fol. 62. 1.”
Source
1832
A.D.
Adam Clarke Methodist
1762–1832
“Is the law then against the promises of God? - Is it possible that the intervention of the law, in reference to one part of the Abrahamic seed, should annul the promise made to the other? It is impossible. For if there had been a law, etc. - If any law or rule of life could have been found out that would have given life - saved sinners from death, and made them truly happy, then righteousness- justification, should have been by that law.”
Source
1871
A.D.
1871
“"Is the law (which involves a mediator) against the promises of God (which are without a mediator, and rest on God alone and immediately)? God forbid." life--The law, as an externally prescribed rule, can never internally impart spiritual life to men naturally dead in sin, and change the disposition. If the law had been a law capable of giving life, "verily (in very reality, and not in the mere fancy of legalists) righteousness would have been by the law (for where life is, there righteousness, its condition, must also be)." But the law does not pretend to give life, and therefore not righteousness; so there is no opposition between the law and the promise. Righteousness can only come through the promise to Abraham, and through its fulfilment in the Gospel of grace.”
Source
Modern · 1953 →

The in-app commentary runs from the Fathers to the early-modern record, then stops — that's where the public-domain sources end, not where the reading does. For the modern reading, follow the sources directly.