That we must not rashly judge of another
In the Gospel according to Luke: “Judge not, that you be not judged: condemn not, that you be not condemned.” Of this same subject to the Romans: “Who are you that judgest another man's servant? To his own master he stands or falls. But he shall stand; for God is able to make him stand.” And again: “Wherefore you are without excuse, O every man that judges: for in that in which you judge another, you condemn yourself; for you do the same things which you judge. But you, who judge those who do evil, and do the same, hope that you yourself shall escape the judgment of God.” Also in the first Epistle of Paul to the Corinthians.: “And let him that thinks he stands take heed lest he fall.” And again: “If any man thinks that he knows anything, he knows not yet in what manner he ought to know.”
Source: The Treatises of Cyprian (New Advent)