Jephthah

Jephthah was the son of a prostitute, driven out by his half-brothers and living as a bandit leader until Gilead's elders begged him to lead their fight against the Ammonites. He made a reckless vow that whatever came out of his house first to greet him after victory would be sacrificed to God, and that turned out to be his own daughter, his only child, a story Judges records without endorsing the vow or explaining why Jephthah felt bound to keep it.