Numbers 30:2

If it is a serious matter to lie to another person, how much more to lie to God. When Scripture describes his majesty, it says that God is in heaven above, and you are on the earth below. This passage was written for us to imitate God, who said, "I will not break my covenant." He says this about the life of each man: that is, if one has vowed abstinence from food, or shaving his head, or the offering of a sheep or a calf. Malachi commands that the best offerings should be brought forth when he says, "Cursed is he who has a male animal in his flock and makes a vow and then offers a blemished animal to the Lord."The daughter of Jephthah preferred to undergo death rather than to render her father's vow unfulfilled and mendacious. She did not know that she was the type of the saving Victim, whom she prefigured in herself. For this reason Jephthah's deed was immune to guilt. It is not a model, because it does not follow the law. The deed was permitted only once, as a sign, for God rejects human sacrifice. Moreover, what is undertaken by children to the disgrace of their parents does not merit the name of vow, despite those wicked doctors and teachers who tell their parents that "whatever you would have received from me is Corban." For God commands us to honor father and mother in all cases. A man who infringes on the vow of his new bride, which she made without her father's approval, [does not sin]. The same applies to a married man who does not consent to a vow his wife made. For what is vowed when the woman is subject to a greater power, if it is not carried out, does not make her guilty. But if the woman becomes a widow or is separated from her husband, her vow is binding. This ancient institution of God is confirmed because the woman was made for the sake of the man, and it is just for her to obey him. There is also that verse from Paul, that the woman should revere the man. Scripture gives a similar explanation for matters concerning affliction of the soul, fasting and other practices, when it says, concerning the month of fasting, "In that month you will afflict your souls."

After these things the law of vows is set down, and Moses uses a new beginning in this legislation; for he says: "A man, a man, whoever shall vow a vow to the Lord." What is the reason for this repeating of the name? As though it did not suffice to have said: "A man who shall vow a vow to the Lord." What is it therefore that he says, "a man, a man," and what this doubled naming of "man" means, does not seem to me to be passed over in silence. The Apostle teaches that there is one inner man and another outer, and that the former is he who is renewed from day to day according to the image of him who created him, but that the latter is the visible one, who is corrupted. When therefore one comes to that advancement, that the law of God may be received and vows offered to the Lord — and no one can offer vows to the Lord except him who has something within himself and in his own substance which he may offer to God — this outer man does not suffice to receive the law of God nor to offer vows alone, for he cannot have anything worthy of God, but it is that inner man who rather has in himself what he may offer to God; for in him is the dwelling of the virtues, in him all understanding of knowledge, in him is the renewal of the divine image. And when he has recovered his form, by which he was made from the beginning by God, and by the restoration of the virtues has received back the beauty of his former shape, then he can now offer vows to God, and then he will now be called not "man" only, but "man, man." For he who does not cultivate the inner man, who takes no care of him, who does not equip him with virtues, does not adorn him with morals, does not exercise him in divine instructions, does not seek the wisdom of God, does not expend labor on the knowledge of the scriptures — this one cannot be called "man, man," but only "man," and an animal man, because that inner one, to whom the name "man" more truly and more nobly belongs, is lulled to sleep in him by carnal vices and overwhelmed by the cares and anxieties of this world, so that not even the naming of his name can be had. Wherefore each of us must strive earnestly that, if perhaps he sees the inner man in himself lying oppressed with the filth of sins and the rubble of vices, he may more quickly remove from him all uncleannesses, more quickly rescue him from every defilement of flesh and blood, be converted…