Cyprian of Carthage, Three Books of Testimonies Against the Jews III.9: That anger must be overcome, lest it constrain us to sin

In Solomon in the Proverbs: “Better is a patient man than a strong man; for he who restrains his anger is better than he who taketh a city.” Also in the same place: “The imprudent man declareth his anger on the same day, but the crafty man hideth away his dishonour.” Of this same thing to the Ephesians: “Be ye angry, and sin not. Let not the sun set upon your wrath.” Also in the Gospel according to Matthew: “Ye have heard that it was said by the ancients, Thou shalt not kill; and whoever shall kill shall be guilty of the judgment. But I say unto you, That every one who is angry with his brother without cause shall be guilty of the judgment.”