Judges 11:29-40

29Then the Ruach Adonai came upon Jephthah, so he marched through Gilead and Manasseh, and passed through Mizpah of Gilead, and from Mizpah of Gilead he crossed over to the children of Ammon.

30Then Jephthah vowed a vow to Adonai and said, “If You will indeed give the children of Ammon into my hand,

31then it will be that whatever comes out of the doors of my house to meet me when I return safely from the children of Ammon, it will be Adonai’s, and I will offer it up as a burnt offering.”

32So Jephthah crossed over to the children of Ammon to fight against them, and Adonai gave them into his hand.

33So he utterly defeated them from Aroer until you come to Minnith—20 towns—and as far as Abel-cheramim. So the children of Ammon were subdued before Bnei-Yisrael.

34Now when Jephthah arrived at his home in Mizpah, behold, his daughter was coming out to meet him with tambourines and with dances. Now she was his only child. Besides her he had no son or daughter.

35Upon seeing her, he tore his clothes and said, “Alas, my daughter! You made me bow down in grief—you’ve made me miserable! For I have opened my mouth to Adonai, and I cannot take it back.”

36“My father, you have opened your mouth to Adonai,” she said to him. “Do to me what proceeded from your mouth—since Adonai brought vengeance on your enemies, the children of Ammon.”

37She said further to her father, “Let this thing be done for me. Let me be alone two months, so that I may go on the mountains and mourn my virginity, I and my companions.”

38“Go!” he said. So he sent her away for two months. So she left, she and her companions, and mourned on the mountains because of her virginity.

39Then at the end of two months she returned to her father, who did with her according to his vow he had made—so she was never intimate with a man. So it became a custom in Israel,

40that the daughters of Israel would go annually to commemorate the daughter of Jephthah the Gileadite four days in a year.