Then after three years I went up to Jerusalem to visit Cephas and remained with him fifteen days.
18. Then after three years. It was not till three years after he had begun to discharge the apostolic office, that he went up to Jerusalem. Thus, he did not, at the outset, receive the calling of men. But lest it should be supposed that he had separate interests from theirs, and was desirous to avoid their society, he tells us that he went up...
What Paul had said more generally, in the preface of this epistle, he now proceeds more particularly to enlarge upon. There he had declared himself to be an apostle of Christ; and here he comes more directly to support his claim to that character and office.
Commenting on Galatians 1:10-24
Then after three years I went up to Jerusalem,.... Not three years after his return to Damascus, but after his conversion; and now it was that he moved to become a member of the church at Jerusalem; but they did not care to admit him, fearing that he was not a disciple, till such time that Barnabas took him, and brought him to the Apostles...