{Not sinners of the Gentiles} (ouk ex ethn(936e) hamart(936c)oi).
The Jews regarded all Gentiles as "sinners" in contrast with
themselves (cf.  Mt 26:45  "sinners" and  Lu 18:32  "Gentiles").
It is not clear whether verses  15-21  were spoken by Paul to
Peter or whether Paul is now simply addressing the Galatians in
the light of the controversy with Peter. Burton thinks that he is
"mentally addressing Peter, if not quoting from what he said to
him."