A.T. Robertson Commentary Galatians 2:11

"But when Cephas came to Antioch, I resisted him to the face, because he stood condemned." — Galatians 2:11 (ASV)

I resisted him to the face (κατα προσωπον αυτω αντεστην). Second aorist active indicative (intransitive) of ανθιστημ. "I stood against him face to face." In Jerusalem Paul faced Peter as his equal in rank and sphere of work. In Antioch he looked him in the eye as his superior in character and courage.

Because he stood condemned (οτ κατεγνωσμενος ην). Periphrastic past perfect passive of καταγινοσκω, old verb to know against, to find fault with. In N.T. only here and 1 John 3:20f.