Jephthah's vow (HAW)
    As [Jephthah] approached his home [following his great
    victory] the maidens of the town came forth, according to the custom of the
    time, to greet the mighty man of valour with songs and dances. In this way,
    Miriam and the women of Israel had celebrated the destruction of Pharaoh's host
    in the Red Sea (Exo 15:20); and later, David's victories over the Philistines
    were acclaimed in the same fashion (1Sa 18:6).
    
    But now, to his consternation and grief, Jephthah beheld
    amongst them his own daughter, and he who should have been enjoying the victor's
    triumph rent his clothes: "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 the Lord,
    and I cannot go back."
    
    However Jephthah's vow be understood, that last phrase shows
    what a sterling character he was. "I cannot go back!" Come what may, his vow to
    God must be performed. Jephthah swore to his own hurt, and changed not. "He that
    doeth these things shall never be moved." For this Jephthah's name is inscribed
    in the Lord's "roll of honour" in Hebrews 11 amongst those who glorified God by
    their faith.
    
    The question of the fate of Jephthah's daughter as a result of
    the vow he made unto the Lord is probably the most discussed problem in the Book
    of Judges. Traditionally the vow of Jephthah has been taken as meaning exactly
    what it says. Nevertheless there are those who believe that Jephthah's daughter
    was not slain and burnt on an altar, but that she was dedicated to life-long
    service of God in connection with the tabernacle. This latter conclusion has the
    weight of evidence behind it. It is those who believe that the maiden became a
    burnt offering who are faced with difficulties.
    
    First, it is tolerably clear that Jephthah was expecting to
    have to give to God, in fulfilment of his vow, a PERSON and not an animal; or to
    be more precise, BOTH a person AND a burnt offering. His words were: "Whatsoever
    cometh forth of the doors of my house to meet me... shall surely be the Lord's."
    There is no point in stressing "whatsoever (as distinct from whomsoever) cometh
    forth": the word "whatsoever" is a Hebrew masculine, for in such a sentence the
    masculine would cover all genders.
    
    But what animal might come to meet Jephthah? The only animals
    that might be offered as a burnt offering were sheep, goats, bullocks, and (for
    the very poorest of the people) pigeons. Would Jephthah be expecting to be met
    by any of these? The only animal that might conceivably go out to meet him would
    be a favourite hound, and that would certainly not make an acceptable offering
    to the Lord.
    
    In any case, Jephthah's vow manifestly signified something of
    considerable value in his eyes -- a real sacrifice, in the modern sense of the
    world.
    
    Since, from the very nature of the vow, it must refer to
    someone over whom Jephthah had full control, the possibilities are limited to
    two: a favourite slave, or servant, or his only daughter.
    
    Consequently, the conclusion becomes inevitable that Jephthah
    was vowing unto God someone for whom he would have real affection, someone whose
    loss he would mourn bitterly. His vow was a vow worth making. It honoured God by
    an offering that was by no means inconsiderable.
    
    Once this vow is thus seen in its true perspective, all other
    details begin to fall into place.
    
    It has already been seen [from his astute handling of
    Scripture earlier in Jdg 11] that Jephthah was no uncouth desperado, but -- like
    the outlaw David -- a devout man well-schooled in the Scriptures. He would
    therefore be no stranger to such passages as the following: "Thou shalt not let
    any of thy seed pass through the fire to Molech, neither shalt thou profane the
    name of thy God: I am the Lord" (Lev 18:21).
    
    
        "Take heed to thyself that thou be not snared by following them, after that they
        be destroyed from before thee; and that thou inquire not after their gods,
        saying, How did these nations serve their gods? even so will I do likewise. Thou
        shalt not do so unto the Lord thy God: for every abomination to the Lord, which
        he hateth, have they done unto their gods; for even their sons and their
        daughters have they burnt in the fire to their gods" (Deu
        12:30,31).
    
        "There shall not be found among you any one that maketh his son or his daughter
        to pass through the fire, or that useth divination, or an observer of times, or
        an enchanter, or a witch" (Deu 18:10).
    Then is it possible that such a man as Jephthah would even
    consider making a human sacrifice? Is it likely that having just returned from
    the slaughter of the Ammonites (whose god had been unable to deliver or prosper
    them), he would then proceed to imitate the rites of Molech, the god of Ammon,
    which were utterly forbidden to Israel?
    
    Again, let it be supposed that Jephthah had sought to offer
    his daughter as a burnt-offering. This could be done only at the altar of the
    Lord, and through the ministration of a priest -- and what priest would condone
    or assist such a flagrant breach of Levitical precept?
    
    And, if the maiden were to die as a sacrifice, would it not be
    an intensely unnatural thing for her to spend the last two months of her life
    away from her father who loved her so much?
    
    It needs to be recognized also that the vowing of persons to
    God was a perfectly normal matter in the life of Israel; the Law made provision
    for such acts of exceptional piety: "Speak unto the children of Israel, and say
    unto them, When a man shall make a singular vow, the persons shall be for the
    Lord by thy estimation" (Lev 27:2). A commutation price, differing for males and
    females and according to the age of the person vowed unto the Lord, might be
    paid. In the case of a male between the ages of twenty and sixty, this payment
    was fifty shekels (for a working man, more than a year's wages?).
    
    Evidently then, the vow took the form of consecrating, in
    effect, the labour value of the person vowed. The practical result, in most
    instances, would be for the commutation price to be paid and the life of the
    individual concerned would proceed normally. 
    
    But, it has been claimed, the same scripture REQUIRES the
    actual sacrifice of such as Jephthah's daughter: "Notwithstanding, no devoted
    thing that a man shall devote unto the Lord of all that he hath, both of man and
    beast, and of the field of his possession, shall be sold, or redeemed: every
    devoted thing is most holy unto the Lord. None devoted, which shall be devoted
    of men, shall be redeemed; abut all shall surely be put to death" (Lev
    27:18,19).
    
    To apply these words to the question under discussion is to
    confuse two very different things, namely (1) that which is vowed; and (2) the
    devoted thing (Hebrew "cherem"; eg, Josh 6:17,18 same word).
    
    Whereas there was always optional redemption of a vow by means
    of a money payment, the "cherem" -- nearly always associated with what was taken
    in war -- normally meant utter destruction (something akin to whole burnt
    offering). Jephthah's vow was the former of these. Lev 27:18,19 describes the
    latter.
    
    There were instances, like Hannah's vowing of her son unto the
    Lord "all the days of his life", when advantage of the commutation arrangement
    was not taken. This is what Jephthah meant when he said: "I cannot go back." His
    daughter was to be given to the Lord all the days of her life. So completely did
    Jephthah feel his indebtedness to the Lord that there was to be no suggestion of
    taking an easy way out. He would pay his vow in the fullest sense, by giving his
    daughter from that time forward for permanent service in the precincts of the
    tabernacle. (WJR).