Galatians 2:7

The gospel of the uncircumcision - The duty of preaching the gospel to the uncircumcised part of the world; that is, to the Gentiles Paul had received this as his unique office when he was converted and called to the ministry (see Acts 9:15; Acts 22:21); and they now perceived that he had been specially intrusted with this office, from the remarkable success which had attended his labors. It is evidently not meant here that Paul was to preach only to the Gentiles and Peter only to the Jews, for Paul often preached in the synagogues of the Jews, and Peter was the first who preached to a Gentile Acts 10:0; but it is meant that it was the main business of Paul to preach to the Gentiles, or that this was especially entrusted to him.

As the gospel of the circumcision - As the office of preaching the gospel to the Jews.

Was unto Peter - Peter was to preach principally to the circumcised Jews. It is evident that until this time Peter had been principally employed in preaching to the Jews. Paul selects Peter here particularly, doubtless because he was the oldest of the apostles, and in order to show that he was himself regarded as on a level in regard to the apostleship with the most aged and venerable of those who had been called to the apostolic office by the personal ministry of the Lord Jesus.