Charles Ellicott Commentary Judges 11:35

"And it came to pass, when he saw her, that he rent his clothes, and said, Alas, my daughter! thou hast brought me very low, and thou art one of them that trouble me; for I have opened my mouth unto Jehovah, and I cannot go back." — Judges 11:35 (ASV)

He tore his clothes. —Compare to Joshua 7:6. By one of the curious survivals that preserve customs for centuries after their meaning has disappeared, every Jew approaching Jerusalem for the first time has to submit to the krie—that is, a cut made in his sleeve, as a sort of symbol of tearing his clothes.

You have brought me very low. —Literally, crushing, you have crushed me.

I have opened my mouth to the Lord. —A vow was not considered binding unless it had been actually expressed in words (Numbers 30:2–3; Numbers 30:7; Deuteronomy 23:23). There were two kinds of vows among the Hebrews—the simple vow, neder (Leviticus 27:2–27), and the “devotion,” or “ban,” cherem (Leviticus 27:28–29). Anything devoted to Jehovah by the cherem was irredeemable, became “a holy of holies” (kodesh kadashim) to Him, and was to be put to death (Leviticus 27:29).

I cannot go back. — Numbers 30:2. Jephthah had not understood until now the horror of human sacrifice. He would neither wish nor dare to draw back from his cherem (Ecclesiastes 5:4–5; Matthew 5:33; Jonah 2:9; Psalms 72:25; Psalms 26:11) merely because the anguish of it would fall so heavily upon himself. The Hebrews had the most intense feeling about the awfulness of breaking an oath or vow, and they left no room for any mental reservations (Leviticus 27:28–29).

Saul was determined to carry out his ban even at the cost of the life of his eldest son, and even Herod Antipas felt obliged to carry out his oath to Herodias, though it involved a deep pang and a haunted conscience. It is clear that not for one moment did it occur to Jephthah to save himself from the agony of bereavement by breaking his ‘ban’ (cherem) as a mere redeemable vow (neder).

The Jews shared in this respect the feelings of other ancient nations. Thus, the Greeks believed that the house of Athamas was under an inexpiable curse because when the Achaeans had been commanded to offer him as a sacrifice for bringing about the death of Phrixus, Cytissorus, the son of Phrixus, intercepted the sacrifice (Herodotus 7.197, § 3; Plato, Minos, 5).

It must be remembered that although his cherem had taken an unusual and unlawful (though far from unknown) form, the idea of such a vow would come far more naturally to a people who, in very recent times as well as afterwards, had devoted whole cities—men, women, children, cattle, and goods—to absolute destruction (Numbers 21:2–3).