John Chrysostom

"Therefore thou art inexcusable, O man; whosoever thou art that judgest; for wherein thou judgest another, thou condemnest thyself." These things he says, with an aim at the rulers, inasmuch as that city then had the rule of the world put into its hands. …

Homily on Romans 5 ↗

Theophylact of Ohrid

We are all people of unequal disposition: sometimes we patronize evil, sometimes we become judges of others' evils, condemning those like ourselves. So, having spoken before about those who approved of the wicked, he now speaks about condemnation and says: "therefore you are inexcusable." That is, you knew that the justice of God consists in worthily punishing the wicked; therefore you also have no excuse, you who condemn those who do the same things that you yourself do. …

Commentary on Romans ↗

Cyprian

That we must not rashly judge of another. In the Gospel according to Luke: "Judge not, that ye be not judged: condemn not, that ye be not condemned." Of this same subject to the Romans: "Who art thou that judgest another man's servant? to his own master he standeth or falleth. But he shall stand; for God is able to make him stand." And again: "Wherefore thou art without excuse, O every man that judgest: for in that in which thou judgest another, thou condemnest thyself; for thou doest the same things which thou judgest. …

Treatise XII Three Books of Testimonies Against the Jews ↗

Thomas Aquinas

After showing that the gentiles did not become just from the knowledge of the truth they had, the Apostle now shows that neither were the Jews made just by the things in which they gloried. Consequently, both of them need the power of the Gospel's grace for salvation. First, therefore, he says that the Jews were not made just by the law; second, that they were not made just by the race in which they gloried: what advantage then has the Jew? (Rom 3:1). Third, that they were not made just by circumcision: what shall we say then? …

Commentary on Romans ↗