Ambrose of Milan

Let your discourses then be flowing, let them be clear and lucid; pour the sweetness of your moral arguments into the ears of the people, and sooth them with the charm of your words, that so they may willingly follow your guidance. But if there be any contumacy or transgression in the people or individuals, let your sermons be of such a character as shall move your audience, and prick the evil conscience, for the words of the wise are as goads. The Lord Jesus too pricked Saul, when he was a persecutor. …

Letter II, To Constantius ↗

Jerome

"The words of the wise are as goads, and as nails fastened by the masters of assemblies, which are given from one shepherd. "The teacher should not be seen to break from the law of God and afterwards to justify teaching by himself, more hastily than Moses not so much of his own will, as first by the anger of God, took teachings therefrom with enthusiasm. …

Commentary on Ecclesiastes ↗

Gregory the Dialogist

Holy preachers are also accustomed to reprove their hearers with sharp words, and to rage with strict severity against their sins: as it is written, The words of the wise are as goads, and as nails fastened deep. But their words are rightly called nails, since they do not know how to handle gently the sins of offenders, but how to pierce them through. Were not the words of John nails, when he said, O generation of vipers, who hath shewed you to flee from the wrath to come? …

Morals on the Book of Job, Book 24 ↗