And unto the Jews I became as a Jew, that I might gain the Jews; to them that are under the {p} law, as under the law, that I might gain them that are under the law;

(p) The word law in this place must be limited to the ceremonial Law.

People's New Testament

9:20 Unto the Jews I became as a Jew. With Jews he lived as a Jew in order to reach them. He observed their distinctions of meats, kept feasts (Ac 18:21), and circumcised Timothy (Ac 16:3). He observed the law to reach those who kept law.

Wesley's Notes

9:20 To the Jews I became as a Jew - Conforming myself in all things to their manner of thinking and living, so far as; I could with innocence. To them that are under the law - Who apprehend themselves to be still bound by the Mosaic law. As under the law - Observing it myself, while I am among them. Not that he declared this to be necessary, or refused to converse with those who did not observe it. This was the very thing which he condemned in St. Peter, Gal 2:14.

Jamieson-Fausset-Brown Bible Commentary

20. I became as a Jew-in things not defined by the law, but by Jewish usage. Not Judaizing in essentials, but in matters where there was no compromise of principle (compare Ac 16:3; 21:20-26); an undesigned coincidence between the history and the Epistle, and so a sure proof of genuineness.

to them that are under the law, as under the law-in things defined by the law; such as ceremonies not then repugnant to Christianity. Perhaps the reason for distinguishing this class from the former is that Paul himself belonged nationally to "the Jews," but did not in creed belong to the class of "them that are under the law." This view is confirmed by the reading inserted here by the oldest manuscripts, versions, and Fathers, "not being (that is, parenthetically, 'not that I am') myself under the law."

Matthew Henry's Concise Commentary

9:15-23 It is the glory of a minister to deny himself, that he may serve Christ and save souls. But when a minister gives up his right for the sake of the gospel, he does more than his charge and office demands. By preaching the gospel, freely, the apostle showed that he acted from principles of zeal and love, and thus enjoyed much comfort and hope in his soul. And though he looked on the ceremonial law as a yoke taken off by Christ, yet he submitted to it, that he might work upon the Jews, do away their prejudices, prevail with them to hear the gospel, and win them over to Christ. Though he would transgress no laws of Christ, to please any man, yet he would accommodate himself to all men, where he might do it lawfully, to gain some. Doing good was the study and business of his life; and, that he might reach this end, he did not stand on privileges. We must carefully watch against extremes, and against relying on any thing but trust in Christ alone. We must not allow errors or faults, so as to hurt others, or disgrace the gospel.

Matthew Henry's Whole Bible Commentary

Verses 19-23

The apostle takes occasion from what he had before discoursed to mention some other instances of his self-denial and parting with his liberty for the benefit of others.

I. He asserts his liberty (v. 19): Though I be free from all men. He was free-born, a citizen of Rome. He was in bondage to none, nor depended upon any for his subsistence; yet he made himself a servant to all, that he might gain the more. He behaved as a servant; he laboured for their good as a servant; he was careful to please, as a servant to his master; he acted in many cases as if he had no privileges; and this that he might gain the more, or make the more converts to Christianity. He made himself a servant, that they might be made free.

II. He specifies some particulars wherein he made himself a servant to all. He accommodated himself to all sorts of people. 1. To the Jews, and those under the law, he became a Jew, and as under the law, to gain them. Though he looked on the ceremonial law as a yoke taken off by Christ, yet in many instances he submitted to it, that he might work upon the Jews, remove their prejudices, prevail with them to hear the gospel, and win them over to Christ. 2. To those that are without the law as without law that is, to the Gentiles, whether converted to the Christian faith or not. In innocent things he could comply with people's usages or humours for their advantage. He would reason with the philosophers in their own way. And, as to converted Gentiles, he behaved among them as one that was not under the bondage of the Jewish laws, as he had asserted and maintained concerning them, though he did not act as a lawless person, but as one who was bound by the laws of Christ. He would transgress no laws of Christ to please or humour any man; but he would accommodate himself to all men, where he might do it lawfully, to gain some. Paul was the apostle of the Gentiles, and so, one would have thought, might have excused himself from complying with the Jews; and yet, to do them good, and win them over to Christ, he did, in innocent things, neglect the power he had to do otherwise, and conformed to some of their usages and laws. And though he might, by virtue of that character, have challenged authority over the Gentiles, yet he accommodated himself, as much as he innocently might, to their prejudices and ways of thinking. Doing good was the study and business of his life; and, so that he might reach this end, he did not stand on privileges and punctilios. 3. To the weak he became as weak, that he might gain the weak, v. 22. He was willing to make the best of them. He did not despise nor judge them, but became as one of them, forbore to use his liberty for their sake, and was careful to lay no stumbling-block in their way. Where any, through the weakness of their understanding, or the strength of their prejudices, were likely to fall into sin, or fall off from the gospel into heathen idolatry, through his use of his liberty, he refrained himself. He denied himself for their sakes, that he might insinuate into their affections, and gain their souls. In short, he became all things to all men, that he might by all means (all lawful means) gain some. He would not sin against God to save the soul of his neighbour, but he would very cheerfully and readily deny himself. The rights of God he could not give up, but he might resign his own, and he very often did so for the good of others.

III. He assigns his reason for acting in this manner (v. 23): This I do for the gospel's sake, and that I may be partaker thereof with you; that is, for the honour of Christ, whose the gospel is, and for the salvation of souls, for which it was designed, and that he and they might communicate in the privileges of it, or partake together of them. For these ends did he thus condescend, deny himself as to his liberty, and accommodate himself to the capacities and usages of those with whom he had to do, where he lawfully might. Note, A heart warmed with zeal for God, and breathing after the salvation of men, will not plead and insist upon rights and privileges in bar to this design. Those manifestly abuse their power in the gospel who employ it not to edification but destruction, and therefore breathe nothing of its spirit.