What does Judges 11:39 mean?
Jephthah fulfilled his vow (Judges 11:30–31). He allowed her two months of mourning with her friends, weeping that she would never marry or have children (Judges 11:37–38). Then, he makes good on his promise. The text is clear that Jephthah fulfilled his promise to God, exactly as he had intended. It's also clear that the result involved Jephthah's daughter never having children. Other than that, there is great controversy about precisely what happens here.The original phrasing of Jephthah's vow referred to giving something to God "as a burnt offering." Some scholars insist Jephthah killed his daughter and burned her body as a sacrifice to the Lord. They interpret his promise as a reflection of the pagan culture, or a misunderstanding of vows.
Other commentators note it is at least possible that Jephthah fulfilled his vow by following Leviticus 27:1–8. That would mean paying some money for her life to the tabernacle, then committing her to lifelong celibate service to the Lord. God clearly forbade human sacrifice in Israel (Deuteronomy 12:31; 18:9–10); Jephthah may have come to understand that more clearly, even if it was his first intention. Alternatively, he may have never planned on human sacrifice, and a form of permanent dedication was always his meaning.
Beyond her lack of a family—which means the end of Jephthah's line (Judges 11:34)—we are only told that this choice brought great grief to her and, later, to other women on her behalf (Judges 11:40).