Charles Ellicott Commentary Judges 11:36

"And she said unto him, My father, thou hast opened thy mouth unto Jehovah; do unto me according to that which hath proceeded out of thy mouth, forasmuch as Jehovah hath taken vengeance for thee on thine enemies, even on the children of Ammon." — Judges 11:36 (ASV)

And she said to him. —To explain this the Septuagint adds the words, “I have opened my mouth to the Lord against or concerning you.” There is, however, no need for the addition. His words would fatally explain themselves, even if he added nothing more.

If you have opened your mouth to the Lord. —The needless and incorrect insertion of the if in the English Version a little weakens the noble heroism of her answer.

Do to me according to that which has proceeded out of your mouth. —While Jephthah, living in times of ignorance which God winked at, must not be judged for that terrible ignorance of God’s nature which led him to offer a sacrifice which, as Josephus says, was “neither lawful nor acceptable to God,” we may well rejoice in the gleam of sunlight which is flung upon the sacred page by his faithfulness in not going back from his vow, though it were to his own hurt (Psalms 15:4), and in the beautiful devotion of his daughter, cheerfully acquiescing in her own sacrifice for the good of her country.

Compare the examples of Iphigenia; of Macaria (Pausanias 1.32); of Anchurus, the son of Midas; of Curtius; of the Decii; of Marius offering his daughter for victory over the Cimbri; and of the Romans during more than one national panic. Our modern poets have happily seized this aspect of the event (see Dante, Paradiso 5.66):

“Though the virgins of Salem lament,
Be the judge and the hero unbent;
I have won the great battle for you,
And my father and country are free.”—Byron.

“When the next moon was rolled into the sky,
Strength came to me that equaled my desire.
How beautiful a thing it was to die
For God and for my sire!”—Tennyson.

“It was not a human sacrifice in the gross sense of the word, not a slaughter of an unwilling victim, but the willing offering of a devoted heart, to free, as she supposed, her father and her country from a terrible obligation... The heroism of father and daughter are to be admired and loved in the midst of the fierce superstition round which it plays like a sunbeam on a stormy sea.”