29 God's Spirit came upon Jephthah. He went across Gilead and Manasseh, went through Mizpah of Gilead, and from there approached the Ammonites. Jephthah made a vow before God: "If you give me a clear victory over the Ammonites, then I'll give to God whatever comes out of the door of my house to meet me when I return in one piece from among the Ammonites - I'll offer it up in a sacrificial burnt offering." 32 Then Jephthah was off to fight the Ammonites. And God gave them to him. He beat them soundly, all the way from Aroer to the area around Minnith as far as Abel Keramim - twenty cities! A massacre! Ammonites brought to their knees by the People of Israel.
34 Jephthah came home to Mizpah. His daughter ran from the house to welcome him home - dancing to tambourines! She was his only child. He had no son or daughter except her. When he realized who it was, he ripped his clothes, saying, "Ah, dearest daughter - I'm dirt. I'm despicable. My heart is torn to shreds. I made a vow to God and I can't take it back!" 36 She said, "Dear father, if you made a vow to God, do to me what you vowed; God did his part and saved you from your Ammonite enemies." 37 And then she said to her father, "But let this one thing be done for me. Give me two months to wander through the hills and lament my virginity since I will never marry, I and my dear friends." 38 "Oh yes, go," he said. He sent her off for two months. She and her dear girlfriends went among the hills, lamenting that she would never marry. At the end of the two months, she came back to her father. He fulfilled the vow with her that he had made. She had never slept with a man. 39 It became a custom in Israel that for four days every year the young women of Israel went out to mourn for the daughter of Jephthah the Gileadite.