Judges 11:1-3, 29-40And Jephthah the Gileadite was strong in strength. He was the son of a woman who was a whore, and Giled begot Jephthah. Giled’s wife also bore him sons, and the sons of the wife grew up and cast out Jephthah, saying to him, ‘You will not inherit in our father’s house, for you are the son of another woman.’ And Jephthah fled from the face of his brothers and settled in the land of Tov, and empty men flocked to him and went out with him. …
And a spirit of the Eternal came upon Jephthah, and he crossed through Gilead and Manasseh and past the watchtower of Gilead, and from the watchtower of Gilead he crossed over to the sons of Ammon. And Jephthah vowed a vow to the Eternal, saying ‘If you will indeed give the sons of Ammon into my hand, then [it will happen that] the one who comes forth from the doors of my house to greet me on my return in peace from the sons of Ammon will be the Eternal’s, and I will offer him up as a holocaust.’
And Jephthah crossed over to the sons of Ammon to fight with them, and the Eternal gave them into his hand. And he battered them from Aroer until you come to Minnith, twenty cities, and until Avil Kamim, (with) very great slaughter; and the sons of Ammon were humbled in the face of the sons of Israel.
And Jephthah came to the point overlooking his house, and behold, his daughter came out to greet him with timbrels and dances. She was his only one; he had no son or daughter besides her. And [it happened that] when he saw her, he tore his garment and said, ‘Ah, my daughter, you have brought me very low, and you have been the cause of my disturbance; I have opened my mouth to the Eternal, and I cannot go back.’
And she said to him, ‘My father, you have opened your mouth to the Eternal; do to me that which came forth from your mouth. After all, the Lord has made revenge for you upon your enemies, the sons of Ammon.’ And she said to her father, ‘Do this thing for me: leave me alone for two months so I can go and descend on the mountains and weep over my virginity, I and my friends.’
And he said, ‘Go.’ And he sent her away for two months, and she and her friends went and wept over her virginity on the mountains. And [it happened that] at the end of two months she went back to her father, and he carried out on her the vow that he had vowed. She had not known a man.
And it became prescribed in Israel. From that day to this, the daughters of Israel go to recall the daughter of Jephthah the Gileadite for four days in the year.