Jephthah, the Gileadite, was an able warrior, but he was the son of a wicked woman, and had fled from his relatives and lived in the land of Tob. There certain rascals gathered about him, and they used to go out on raids with him.
After a time the Ammonites made war against the Israelites. Then the elders of gilead went to bring Jephthah from the land of Tob, and they said to him, "Come and be our commander, that we may fight against the Ammonites." But Jephthah said to the elders of Gilead, "Are you not the men who hated me and drove me out of my father's house? Why then do you come to me now when you are in trouble?" But the elders of Gilead said to Jephthah, "This is why we have now turned to you, that you may go with us and fight against the Ammonites, and you shall be our chief, even over all the people who live in Gilead." Then Jephthah said to the rulers of Gilead, "If you take me back to fight against the Ammonites and the LORD gives me the victory over them, I shall be your chief." The elders of Gilead replied, "the LORD shall be a witness between us; we swear to do as you say."
Then Jephthah went with the elders of Gilead, and the people made him chief and commander over them. Jephthah also made this vow to the LORD: "If thou wilt deliver the Ammonites into my power, then whoever comes out of the door of my house to meet me, when I return victorious from the Ammonites, shall be the LORD's, and I will offer that one as an offering to be burned with fire."
So Jephthah went out to fight against the Ammonites; and the LORD gave him the victory over them, and delivered them into his hands. But when he came home to Mizpah, his daughter was just coming out to meet him with tambourines and choral dances. She was his only child; besides this one he had neither son nor daughter. So when he saw her, he tore his clothes and said, "Oh, my daughter, you have stricken me! It is you who are the cause of my woe! for I have made a solemn vow to the LORD and cannot break it." She said to him, "My father, you have made a solemn vow to the LORD; do to me what you have promised, since the LORD has punished your enemies the Ammonites. But let this favor be granted me: spare me two months that I may go out upon the mountains with those who would have been my bridesmaids and lament because I will never become a wife and mother." He said, "Go."
So he sent her away for two months with her friends, and she mourned on the mountains because she would never become a wife and mother. At the end of two months she returned to her father, who did what he had vowed to do, even though she had never been married. So it became a custom in Israel: each year the women of Israel go out for four days to bewail the death of the daughter of Jephthah, the Gileadite.