Judges 11:29-39 New American Bible (Revised Edition) (NABRE)
Jephthah’s Vow. 29 The spirit of the Lord came upon Jephthah. He passed through Gilead and Manasseh, and through Mizpah of Gilead as well, and from Mizpah of Gilead he crossed over against the Ammonites. 30 [a]Jephthah made a vow to the Lord. “If you deliver the Ammonites into my power,” he said, 31 “whoever comes out of the doors of my house to meet me when I return from the Ammonites in peace shall belong to the Lord. I shall offer him up as a burnt offering.”
32 Jephthah then crossed over against the Ammonites to fight against them, and the Lord delivered them into his power. 33 He inflicted a very severe defeat on them from Aroer to the approach of Minnith—twenty cities in all—and as far as Abel-keramin. So the Ammonites were brought into subjection by the Israelites. 34 When Jephthah returned to his house in Mizpah, it was his daughter who came out to meet him, with tambourine-playing and dancing. She was his only child: he had neither son nor daughter besides her. 35 When he saw her, he tore his garments and said, “Ah, my daughter! You have struck me down and brought calamity upon me. For I have made a vow[b] to the Lord and I cannot take it back.” 36 “Father,” she replied, “you have made a vow to the Lord. Do with me as you have vowed, because the Lord has taken vengeance for you against your enemies the Ammonites.” 37 Then she said to her father, “Let me have this favor. Do nothing for two months, that I and my companions may go wander in the mountains to weep for my virginity.” 38 “Go,” he replied, and sent her away for two months. So she departed with her companions and wept for her virginity in the mountains. 39 At the end of the two months she returned to her father, and he did to her as he had vowed. She had not had relations with any man.
It became a custom in Israel