John Chrysostom, on Acts 20:21

“Testifying both to Jews and Gentiles penance towards God, and faith in our Lord Jesus Christ.”

“"Both Jews, and Greeks." Not (addressing myself) to you alone. "Testifying:" here, the boldness of speech: and that, even though we do no good, yet we must speak: for this is the meaning of "testifying," when we speak to those who do not pay attention: and so the word diamarturasthai is for the most part used. "I call heaven and earth to witness" (Deut. iv. 26), diamarturomai, Moses, says: and now Paul himself, Diamarturomenoj "both to Jews and Greeks repentance toward God." What testifiest thou? That they should be careful about their manner of life: that they should repent, and draw near to God. "Both to Jews and Greeks"-for neither did the Jews know Him-both by reason of their works, he says, "repentance towards God," and, by reason that they knew not the Son, he adds, "and faith in the Lord Jesus."”

Imported from an open dataset — not yet checked against the printed edition.