Jephthah vowed that if the Lord granted him success against the Ammonites, then whatever greeted him first upon his return, he would offer as a sacrificial burnt offering (Judg. 11:30–31). Much to his sorrow, Jephthah’s daughter was the first to approach him. As a result, many conclude that Jephthah actually engaged in human sacrifice.
An alternative, and superior view, is that Jephthah sacrificed his daughter to lifetime service in the tabernacle, not as a burnt offering. The text says that Jephthah’s daughter accepted her father’s vow but asked to be allowed to go to the mountains and “weep … because I will never marry” (Judg. 11:37). If she were going to be killed, she would have far more to lament than her perpetual virginity. After the two months were completed, Jephthah “did to her as he had vowed. And she was a virgin” (Judg. 11:39). Notice that the text does not say, “she was sacrificed as a burnt offering.” Also, note the repeated emphasis on the unmarried, virginal state of Jephthah’s daughter. Committing her to remain unmarried implied another kind of loss for Jephthah; verse 34 clarifies that “she was an only child. Except for her he had neither son nor daughter.” So Jephthah did not keep his word literally by killing his daughter, but rather he sacrificed his daughter by giving her to tabernacle service. As a result, he would not have any heirs.
Believers need to take the vows we make to the Lord seriously; like Jephthah, we are responsible to keep them even if it will require us to sacrifice our hopes and plans for life.