19 Whereupon Joseph her husband, being a just man, and not willing publicly to expose her, was minded to put her away privately.
Pseudo-Augustine: Joseph, understanding that Mary was with child, is perplexed that it should be thus with her whom he had received from the temple of the Lord, and had not yet known, and resolved within himself, saying, What shall I do? Shall I proclaim it, or shall I overlook it? If I proclaim it, I am indeed not consenting to the adultery; but I am running into the guilt of cruelty, for by Moses’ law she must be stoned. If I overlook it, I am consenting to the crime, and take my portion with the adulterers. Since then it is an evil to overlook the things, and worse to proclaim the adultery, I will put her away from being my wife.
Ambrose: St. Matthew has beautifully taught how a righteous man ought to act, who has detected his wife’s disgrace; so as at once to keep himself guiltless of her blood, and yet pure from her defilements; therefore it is he says, “Being a just man.”
Augustine: If you alone have knowledge of a sin that any has committed against you, and desire to accuse him thereof before men, you do not herein correct, but rather betray him. But Joseph, “being a just man,” with great mercy spared his wife, in this great crime of which he suspected her.
Jerome: This may be considered a testimony to Mary, that Joseph, confident in her purity, and wondering at what had happened, covered in silence that mystery which he could not explain.
Scripture from the Douay-Rheims Bible. Commentary from St. Thomas Aquinas, Catena Aurea, Vol. I (London: Rivington, 1842).