Albert Barnes Commentary 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." — Galatians 2:12 (ASV)

For before that certain came. These were some of the Jews who had been converted to Christianity. They evidently observed the rites of the Jewish religion in the strictest manner.

From James.

Whether they were sent by James or came of their own accord is unknown. It is evident only that they had been close to James in Jerusalem, and they undoubtedly pleaded his authority. James had nothing to do with the course they pursued. However, the meaning of the whole passage is that James was a leading man in Jerusalem and that the rites of Moses were observed there. When they came down to Antioch, they naturally observed those rites and insisted that others should do so as well.

It is very evident that in Jerusalem the distinctive rites of the Jews were observed for a long time by those who became Christian converts. They would not stop observing them at once, as this would needlessly shock the prejudices of their countrymen .

He did eat with the Gentiles. Peter had been taught this in the remarkable vision he saw, as recorded in Acts 10. He had learned that God intended to break down the dividing wall between Jews and Gentiles, and he associated with them familiarly and partook of their food with them. He evidently disregarded the distinctive laws of the Jews about food and drink and partook of the common food that was in use among the Gentiles. In this way, he showed his belief that all people were henceforth to be regarded as on the same level, and that the distinctive institutions of the Jews were not to be considered binding or to be imposed on others.

But when they were come, he withdrew and separated himself. He withdrew from the Gentiles, and probably from the Gentile converts to Christianity. The reason he did this is stated: he feared those who were of the circumcision, that is, those who had been Jews. Whether they demanded this of him, whether they confronted him in debate, or whether he silently separated himself from the Gentiles without their having said anything to him, is unknown.

But he feared the effect of their opposition; he feared their reproaches; he feared the report that would be made to those in Jerusalem; and perhaps he apprehended that a tumult would be stirred up, and a persecution begun in Antioch by the Jews who lived there. This is a melancholy illustration of Peter's characteristic trait.

We see in this act the same Peter who trembled when he began to sink in the waves, the same Peter who denied his Lord. Bold, ardent, zealous, and ready, he was at the same time timid and often irresolute, and he often had occasion for the deepest humility and the most poignant regrets for the errors of his conduct.

No one can read his history without loving his ardent and sincere attachment to his Master; yet no one can read it without a tear of regret that he was allowed in this way to harm his cause. No man loved the Savior more sincerely than he did, yet his constitutional timidity and irresolute character often led him to courses of action apt to deeply wound his cause.