Answer
In Judges 11:30-31, Jephthah, a judge of Israel, made a foolish vow that if God gave him victory in the upcoming battle, he would sacrifice whatever first came out of his door when he came home. Jephthah was victorious in the battle against the Ammonites (Judges 11:32-33). When Jephthah returned home after the battle, his daughter came to greet him (Judges 11:34). Jephthah was devastated and stated that he had made a vow to the Lord that he could not break (Judges 11:35). Jephthah’s daughter asked for a two month “reprieve,” and Jephthah granted her request (Judges 11:36-38). The passage then states that Jephthah “did to her as he had vowed” (Judges 11:39).
The Bible does not explicitly state that Jephthah sacrificed his daughter as a burnt offering. Since his daughter was mourning the fact that she would never marry instead of mourning that she was about to die (Judges 11:36-37), this possibly indicates that Jephthah gave her to the tabernacle as a servant instead of sacrificing her. However, again, Judges 11:39 does seem to indicate that he did follow through with the sacrifice: "He did to her as he had vowed."
Whatever the case, God had specifically forbidden offering human sacrifices, so it was absolutely not God’s desire for Jephthah to sacrifice his daughter (Leviticus 20:1-5). Jeremiah 7:31; 19:5; and 32:35 clearly indicate that the idea of human sacrifice has "never even entered God’s mind." The account of Jephthah and his daughter serves as an example for us to not make foolish vows or oaths. It should also serve as a warning to make sure any vow we make is something that is not in violation of God’s Word.
