29 Then the Spirit of the LORD came upon Jephthah, and he passed through Gilead and Manasseh and passed through Mizpeh of Gilead, and from Mizpeh of Gilead he went unto the sons of Ammon. 30 And Jephthah vowed a vow unto the LORD and said, If thou shalt without fail deliver the sons of Ammon into my hands, 31 whoever comes forth of the doors of my house to meet me when I return in peace from the sons of Ammon shall surely be the LORD’s, and I will offer them up for a burnt offering. 32 So Jephthah went over unto the sons of Ammon to fight against them, and the LORD delivered them into his hands. 33 And he smote them from Aroer, even unto Minnith twenty cities, and unto the plain of the vineyards, with a very great slaughter. Thus the sons of Ammon were subdued before the sons of Israel.
34 And Jephthah came to Mizpeh unto his house, and, behold, his daughter came out to meet him with timbrels and with dances; and she was his only child; beside her he had neither son nor daughter. 35 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 those that trouble me, for I have opened my mouth unto the LORD, and I cannot go back. 36 And she said unto him, My father, if thou hast opened thy mouth unto the LORD, do to me according to that which has proceeded out of thy mouth, forasmuch as the LORD has taken vengeance for thee of thine enemies, even of the sons of Ammon. 37 And she said again unto her father, Let this thing be done for me; let me alone two months, that I may go up and down upon the mountains and bewail my virginity, I and my companions. 38 And he said, Go. And he sent her away for two months, and she went with her companions and bewailed her virginity upon the mountains. 39 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 had never known a man. From here came the custom in Israel 40 that the daughters of Israel went yearly to lament the daughter of Jephthah, the Gileadite, four days in a year.