John Chrysostom — as excerpted in the Catena Aurea on Matthew 7:1-2

“Otherwise; He does not forbid us to judge all sin absolutely, but lays this prohibition on such as are themselves full of great evils, and judge others for very small evils. In like manner Paul does not absolutely forbid to judge those that sin, but finds fault with disciples that judged their teacher, and instructs us not to judge those that are above us.”