Deuteronomy 19

Deuteronomy 19:5

Gregory the Dialogist: For indeed we go with a friend into the wood as often as we betake ourselves to look into the delinquencies of subordinates. And we hew wood in simplicity of heart, when with pious intention we cut off the vices of delinquents. But the axe flies from the hand, when rebuke is drawn on to asperity more than need requires. And the iron leaps from the helve, when out of reproof issues speech too hard. And he smites and slays his friend, because overstrained contumely cuts him off from the spirit of love. For the mind of one who is reproved suddenly breaks out into hatred, if immoderate reproof charges it beyond its due. But he who smites wood incautiously and destroys his neighbour must needs fly to three cities, that in one of them he may live protected; since if, betaking himself to the laments of penitence, he is hidden under hope and charity in sacramental unity, he is not held guilty of the perpetrated homicide. — The Book of Pastoral Rule, Part 2, Chapter 10

Jerome: The very words of Scripture indicate that even ignorance is a sin. This is why Job offers holocausts for his sons, lest perchance they may have sinned unwittingly in thought. And if a man is killed by the iron of an axe that flies off the handle when a man is hewing wood, the wood hewer is ordered to flee to a city of refuge and remain in that place until the death of the high priest. That is to say, [he remains there] until he is redeemed by the blood of the Savior, either in the house of baptism or by repentance, which supplies the efficacy of the grace of baptism through the ineffable mercy of the Savior. [The Savior] does not wish anybody to perish, nor does he find his delight in the death of sinners, but [he would] rather that they be converted from their way and live. — Against the Pelagians 1.33

Deuteronomy 19:14

Ambrose of Milan: Enjoin them too (as I have borrowed a figure from agriculture) to preserve inviolate the laws of common boundary, and to guard those paternal landmarks which the law protects. The affection of a neighbour often exceeds the love of a brother, for the one is often afar off, the other nigh at hand; the witness of your whole life, and judge of your conduct. — Letters 1-10

Ambrose of Milan: But on the contrary, if your eye has looked upon a woman to covet her, you have opened a wound, you have driven a weapon into your body. Your very members become tools of sin. If you look upon the property of orphans and drive them from the dwellings of their fathers, you are changing the landmarks that your forefathers set. Your members are tools of iniquity. And so the passions are the author of guilt and not the flesh, for the flesh is the servant of the will. — On Jacob and the Blessed Life

Deuteronomy 19:15

2 Corinthians (13:1-2): This is the third time I am coming to you. In the mouth of two or three witnesses shall every word be established. [Deuteronomy 19:15] I told you before, and foretell you, as if I were present, the second time; and being absent now I write to them which heretofore have sinned, and to all other, that, if I come again, I will not spare

Augustine of Hippo: Therefore if a people composed of a great multitude was found a false witness, how must it be understood, “In the mouth of two or three witnesses every word shall stand,” except that in this way. The Trinity, in which is unending stability of truth, was revealed through a mystery. Do you want to have a good case? Have two or three witnesses, the Father and the Son and the Holy Spirit. — TRACTATE ON THE GOSPEL OF John 36.10.1

Augustine of Hippo: As a matter of fact, a single witness generally speaks the truth, while a mob may tell lies. And the world, in its conversion to Christianity, believed one apostle preaching the gospel rather than the mistaken multitude who persecuted him. — AGAINST FAUSTUS, A MANICHAEAN 16.13

Cyril of Jerusalem: [Christ] did then truly rise, and after he had risen, he was seen again by his disciples. And the twelve disciples were witnesses of his resurrection, testifying not with words meant to please but contending for the truth of the resurrection even unto torture and death. Further, “on the word of two or three witnesses every word may be confirmed,” according to Scripture. There are twelve witnesses to the resurrection of Christ, and do you still disbelieve in the resurrection? — Catechetical Lecture 4.12

Matthew (18:15-17): Moreover if thy brother shall trespass against thee, go and tell him his fault between thee and him alone: if he shall hear thee, thou hast gained thy brother. But if he will not hear thee, then take with thee one or two more, that in the mouth of two or three witnesses every word may be established. [Deuteronomy 19:15] And if he shall neglect to hear them, tell it unto the church: but if he neglect to hear the church, let him be unto thee as an heathen man and a publican.

Maximus of Turin: At the birth of the Savior, then, there was fulfilled that divine sentence which says, “Every word shall stand with two or three witnesses.” For see, the Word of God is born with the Trinity as witness. For indeed, in the womb of holy Mary—when the Holy Spirit comes upon her, when the Most High overshadows her, when Christ is begotten—there is implied a confession of faith in him. — SERMON 61B.3