Judges 11:34-40 - Jephthah's Daughter
34 Then Jephthah came back to his house in Mizpah, and his daughter came out, meeting him on his way with music and with dances; she was his only child; he had no other sons or daughters. 35 And when he saw her he was overcome with grief, and said, Ah! my daughter! I am crushed with sorrow, and it is you who are the chief cause of my trouble; for I have made an oath to the Lord and I may not take it back.
36 And she said to him, My father, you have made an oath to the Lord; do then to me whatever you have said; for the Lord has sent a full reward on your haters, on the children of Ammon. 37 Then she said to her father, Only do this for me: let me have two months to go away into the mountains with my friends, weeping for my sad fate.
38 And he said, Go then. So he sent her away for two months; and she went with her friends to the mountains, weeping for her sad fate. 39 And at the end of two months she went back to her father, who did with her as he had said in his oath: and she had never been touched by a man. So it became a rule in Israel, 40 For the women to go year by year sorrowing for the daughter of Jephthah the Gileadite, four days in every year.