John Chrysostom

"But why dost thou judge thy brother? or why dost thou set at nought thy brother?" And so he seems to be setting them upon a level, but from that he has said, he shows that the difference between them is great. First then by the appellation of "brother" he does away with disputatiousness, and then also by calling that awful day to their mind. …

Homily on Romans 25 ↗

Theophylact of Ohrid

You, the non-eater, why do you condemn your brother who eats, as lacking self-control, because he eats? He is your brother; you must not despise your own member. Will you give an answer for him? He himself will stand before the judgment and will bear the punishment himself. Do you see how, in addressing the mature one, he strikes fear into the very one who Judaizes, as one who must give an account at the dreadful judgment?

Commentary on Romans ↗

Thomas Aquinas

Then when he says, but you, why do you judge, he presents the third reason, which is based on the future judgment. In regard to this he does three things: first, he suggests that a judgment at present is unnecessary, saying: but you, why do you judge, i.e., of what use or need is your judgment, your brother, rashly judging hidden matters not committed to your judgment? Or you, who are judged, why do you despise your brother, regarding as nothing the fact that you are judged by him? Why does each one despise his brother? (Mic 2:10). …

Commentary on Romans ↗