Judges 11:30-40

And Jephthah vowed a vow unto Jehovah, and said, If thou wilt indeed deliver the children of Ammon into my hand, then it shall be, that whatsoever cometh forth from the doors of my house to meet me, when I return in peace from the children of Ammon, it shall be Jehovah’s, and I will offer it up for a burnt-offering. So Jephthah passed over unto the children of Ammon to fight against them; and Jehovah delivered them into his hand. And he smote them from Aroer until thou come to Minnith, even twenty cities, and unto Abel-cheramim, with a very great slaughter. So the children of Ammon were subdued before the children of Israel. And Jephthah came to Mizpah unto his house; and, behold, his daughter came out to meet him with timbrels and with dances: and she was his only child; besides her he had neither son nor daughter. And it came to pass, when he saw her, that he rent his clothes, and said, Alas, my daughter! thou hast brought me very low, and thou art one of them that trouble me; for I have opened my mouth unto Jehovah, and I cannot go back. And she said unto him, My father, thou hast opened thy mouth unto Jehovah; do unto me according to that which hath proceeded out of thy mouth, forasmuch as Jehovah hath taken vengeance for thee on thine enemies, even on the children of Ammon. And she said unto her father, Let this thing be done for me: let me alone two months, that I may depart and go down upon the mountains, and bewail my virginity, I and my companions. And he said, Go. And he sent her away for two months: and she departed, she and her companions, and bewailed her virginity upon the mountains. And it came to pass at the end of two months, that she returned unto her father, who did with her according to his vow which he had vowed: and she knew not man. And it was a custom in Israel, that the daughters of Israel went yearly to celebrate the daughter of Jephthah the Gileadite four days in a year.