For before certain men came from James, he did eat with the Gentiles: but when they were come, he withdrew and separated himself, fearing them who were of the circumcision.
All Commentaries on Galatians 2:12 Go To Galatians 2
Gaius Marius Victorinus
AD 400
But in what way was Peter sinning? He had not adopted this ruse to bring in the Jews, meeting them on their own terms (which Paul himself had done and glories in having done, meeting the Jews on their own terms but for their profit). Rather, the sin of Peter lay in the fact that he withdrew, through fear of those who were of the circumcision. –.