Thematic Bible: Jephthah, of his daughter

And Jephthah made a vow to the Lord and said, If You will indeed give the Ammonites into my hand, Then whatever or whoever comes forth from the doors of my house to meet me when I return in peace from the Ammonites, it shall be the Lord's, and I will offer it or him up as a burnt offering.

Then Jephthah came to Mizpah to his home, 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. And when he saw her, he rent his clothes and said, Alas, my daughter! You have brought me very low, and you are the cause of great trouble to me; for I have opened my mouth [in a vow] to the Lord, and I cannot take it back. And she said to him, My father, if you have opened your mouth to the Lord, do to me according to what you have vowed, since the Lord has taken vengeance for you on your enemies, the Ammonites. read more.
And she said to her father, Let this thing be done for me; let me alone two months, that I may go and wander 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 went with her companions and bewailed her virginity upon the mountains. At the end of two months she returned to her father, who did with her according to his vow which he had vowed. She never mated with a man. This became a custom in Israel -- " That the daughters of Israel went yearly to mourn the daughter of Jephthah the Gileadite four days in a year.