Galatians 2:12

For before that certain came from James, he ate with the Gentiles; but when they came, he drew back and separated himself, fearing them that were of the circumcision. [The Jews regarded it as unlawful to have social intercourse with, or to eat with, Gentiles; but Peter's great vision, teaching the fact that God was no respecter of races or persons, bore especially on the social difference (Acts 10:11-16). Peter, therefore, instructed by the vision, ate with the Gentiles, and defended his conduct in so doing (Acts 11:3-4; Acts 11:12). He therefore knew perfectly what was right and lawful in the matter, but, fearing those who came from James, he played the coward, being, as Alford says, "ever the first to recognize, and the first to draw back from great truths." Peter, therefore, to avoid the censure of these Jerusalem critics, began to withdraw from the Gentiles, and finally to separate himself altogether. Such a withdrawal would mean that Peter could not take the communion with the Gentiles. The "certain" is contemptuous, and corresponds to the "some" of Galatians 1:7. It is not likely that James gave these men any authority for what they did. See his words at Acts 15:19; and those of the decree, Acts 15:24. But James stood in high favor with the Jewish party, and hence, in his absence, would readily be quoted as sanctioning the teachings of that party.]