So what happened to Jephthah's daughter, was she offered as a human sacrifice or something else? A quick reading could lead to this conclusion, but read it again and another option appears. In a previous post, the circumstances of this story was developed, but no answer was given to her fate. Among Jewish and Christian commentators, two basic views dominate. One is she was tragically sacrificed and the other is her sacrifice was a life of perpetual virginity wholly devoted to the service of God.
Let's weigh both views.
1. A Human Sacrifice. The greatest argument for this view is it is the plain reading of the text. This was common among ancient Rabbinical writers, and along with their comments a tradition emerged about Jephthah himself.
Among these ancient Jews arose a belief Jephthah was ultimately punished for this act along with the contemporary high priest, Phineas, who could have annulled the vow but was too proud to act. Phineas was punished by God removing His Spirit from him, a grave curse of loneliness for a spiritual leader familiar with the communion of His God. Jephthah's body, upon natural death or via capital punishment, was cut into pieces and buried throughout the cities of Gilead.
The Fathers of the Church without exception (that I could find) assume human sacrifice occurred. Their approach to the OT was different than ours today, neither examining texts with an eye toward defending repulsive behavior, nor condoning these acts as examples for behavior, they are looking for Christ. They know the whole of the OT and NT condemn murder and human sacrifice. They bemoan the vow of Jephthah and see it as a warning to us all about oaths and rash promises before God.
Yet they see in the daughter a willful sacrifice--a foreshadowing of the sacrifice of Christ. In a sense, she is laying down her life for the sin of her father, "for no greater love is this than a man lay down his life for his neighbor". And because she is a woman who "knows no man", she typifies the Virgin Mary who laid down her life for her people, and all mankind, to bear the Savior of the world.
2. Perpetual Virginity. This view draws power from the ambiguity of the Scriptural language, the circumstances surrounding her fate, Jephthah's hero status in the NT book of Hebrews, and the inconsistency such an action is to the morality of the Torah.
The passage is not fully explicit that she was sacrificed. Jephthah's original vow is oriented toward the giving of a person to God rather than an animal. From the beginning, even if the daughter had not greeted him, he assumes the "sacrifice" would be human. The language could easily read the person would be offered like a burnt offering. A burnt offering was totally consumed by fire, and represented a person's total dedication and commitment to God for the animal being burned was a placeholder for the life of the one sacrificing, proclaiming to God and community their life was not their own but wholly dedicated to the worship and service of God.
Her circumstances upon learning her fate suggest not death but perpetual virginity. She request time to mourn together with her fellow women, a mourning not over death but over the prospect of never entering marriage and bearing children. This was self-imposed barrenness. The Bible is peppered with stories of this fear, and subsequent miraculous conceptions and birth. For children were extension of oneself and carried on the memory of the parent, granting a type of immortality of memory. To be barren was like erasing one's life from the earth as if you never existed. To is akin to being wholly annihilated by fire like a burnt offering.
Although not common, children could be offered to the Temple/Tabernacle in perpetual service to God, such as Samuel. In the NT, the widow Anna at Christ's presentation, was such a servant on the Temple grounds. Psalm 45 hints at this as well, and the Virgin Mary herself was offered up to the Temple as a servant.
Both views require us to consider the sacrifice of Christ and our own commitment to God, whether it is partial or whole.
Are you convinced about either?