But when I saw that they walked not {l} uprightly according to the {m} truth of the gospel, I said unto Peter before them all, If thou, being a Jew, livest after the manner of Gentiles, and not as do the Jews, why {n} compellest thou the Gentiles to live as do the Jews?

(l) Literally, with a right foot, which he sets against halting and hypocrisy, which is a backwards state.

(m) He calls the truth of the Gospel, both the doctrine itself, and also the use of doctrine, which we call the practice.

(n) He says they were forced who lived as Jews by Peter's example.

People's New Testament

2:14 But when I saw... I said unto Peter. It was time to act decisively. Antioch was a great center. It was important that no wrong influences go forth from that center. Hence Paul administered the stern rebuke to Peter which follows.

Before them all. The rebuke was on a public occasion.

If thou, being a Jew, livest after the manner of Gentiles. He had, right there in Antioch, lived with the Gentile Christians according to their customs (Ga 2:12).

Why compellest thou the Gentiles to live as do the Jews? Now, he insisted, at least by his example, that the Gentile Christians should become Jews. He virtually refused to fellowship them.

Wesley's Notes

2:14 I said to Cephas before them all - See Paul single against Peter and all the Jews! If thou being a Jew, yet livest, in thy ordinary conversation, after the manner of the gentiles - Not observing the ceremonial law, which thou knowest to be now abolished. Why compellest thou the gentiles - By withdrawing thyself and all the ministers from them; either to judaize, to keep the ceremonial law, or to be excluded from church communion ?

Jamieson-Fausset-Brown Bible Commentary

14. walked not uprightly-literally, "straight": "were not walking with straightforward steps." Compare Ga 6:16.

truth of the gospel-which teaches that justification by legal works and observances is inconsistent with redemption by Christ. Paul alone here maintained the truth against Judaism, as afterwards against heathenism (2Ti 4:16, 17).

Peter-"Cephas" in the oldest manuscripts

before . all-(1Ti 5:20).

If thou, &c.-"If thou, although being a Jew (and therefore one who might seem to be more bound to the law than the Gentiles), livest (habitually, without scruple and from conviction, Ac 15:10, 11) as a Gentile (freely eating of every food, and living in other respects also as if legal ordinances in no way justify, Ga 2:12), and not as a Jew, how (so the oldest manuscripts read, for 'why') is it that thou art compelling (virtually, by thine example) the Gentiles to live as do the Jews?" (literally, to Judaize, that is, to keep the ceremonial customs of the Jews: What had been formerly obedience to the law, is now mere Judaism). The high authority of Peter would constrain the Gentile Christians to regard Judaizing as necessary to all, since Jewish Christians could not consort with Gentile converts in communion without it.

Matthew Henry's Concise Commentary

2:11-14 Notwithstanding Peter's character, yet, when Paul saw him acting so as to hurt the truth of the gospel and the peace of the church, he was not afraid to reprove him. When he saw that Peter and the others did not live up to that principle which the gospel taught, and which they professed, namely, That by the death of Christ the partition wall between Jew and Gentile was taken down, and the observance of the law of Moses was no longer in force; as Peter's offence was public, he publicly reproved him. There is a very great difference between the prudence of St. Paul, who bore with, and used for a time, the ceremonies of the law as not sinful, and the timid conduct of St. Peter, who, by withdrawing from the Gentiles, led others to think that these ceremonies were necessary.