John Chrysostom

Wherefore neither with this was He satisfied, but unfolds also the very nature of the war, signifying it to be far more grievous even than a civil war; and He saith, "I am come to set a man at variance against his father, and the daughter against her mother, and the daughter-in-law against her mother-in-law." For not friends only, saith He, nor fellow citizens, but even kinsmen shall stand against one another, and nature shall be divided against herself. …

Homily on the Gospel of Matthew 35 ↗

Jerome

For I have come to set a man against his father, and a daughter against her mother, and a daughter-in-law against her mother-in-law; and a man's enemies will be those of his own household. This passage is written in almost the same words in the prophet Micah (Micah 7). And it should be noted whenever a testimony from the Old Testament is presented, whether the meaning alone or also the wording agrees.

Commentary on Matthew ↗

Hilary of Poitiers

The five inhabiting one house, whom He divides three against two, and two against three, we may explain thus; The three are the three parts of man, the body, the soul, and the will; for as the soul is bestowed in the body, so the will has power of using both in any way it chooses; and thence when a law is given it is given to the will. But this is only found in those who were first formed by God. …

Catena Aurea by Aquinas ↗

Thomas Aquinas

But someone could say: You have come to separate. Between whom have you come? Was it not between distant persons and strangers? He shows that it was not, but between those most closely united. For, he says, I have come to set a man against his father... For the closest union is twofold: one is the natural union; the other, domestic, or of the household; therefore, he brings a word against both. Natural friendship is based on a natural act, which is generation, or the union of man and wife; domestic or household, on kinship. …

Commentary on Matthew ↗