Cyprian

I had treated you with contempt, Demetrian, as you railed with sacrilegious mouth against God, who is one and true, and frequently cried out with impious words, thinking it more fitting and better to ignore with silence the ignorance of a man in error than to provoke with speech the fury of a man in madness. …

Treatise V. An Address to Demetrianus 1 ↗

Ambrose of Milan

[David] used not to answer the enemy that provoked him, the sinner that exasperated him. As he says elsewhere, "As though he were deaf he heard not them that speak vanity and imagine deceit, and as though he were dumb he opened not his mouth to them." Again, in another place, it is said, "Answer not a fool according to his folly, lest thou also be like to him."The first duty then is to have due measure in our speech. In this way a sacrifice of praise is offered up to God. Thus a godly fear is shown when sacred Scriptures are read. …

On the Duties of the Clergy 1.10.34-35 ↗

Bede

Do not answer a fool according to his foolishness, etc. Answer a fool according to his foolishness, lest he be wise in his own eyes. These should not be seen as mutually contradictory, not to answer a fool according to his foolishness, and to answer a fool according to his foolishness: for both correspond according to the diversity of times and persons, while the fool is also disregarded because he does not receive wisdom, and foolish pride is checked by another kind of foolishness, just as the Apostle also says, I have become a …

Commentary on Proverbs ↗