Judges 11:34-39

34When Jephthah went to his home in Mizpah, there was his daughter, coming out to meet him with tambourines and dancing! She was his only child; he had no other son or daughter besides her.

35When he saw her, he tore his clothes and said, “No! Not my daughter! You have devastated me! You have brought great misery on me. I have given my word to the Lord and cannot take it back.”

36Then she said to him, “My father, you have given your word to the Lord. Do to me as you have said, for the Lord brought vengeance on your enemies, the Ammonites.”

37She also said to her father, “Let me do this one thing: Let me wander two months through the mountains with my friends and mourn my virginity.”

38“Go,” he said. And he sent her away two months. So she left with her friends and mourned her virginity as she wandered through the mountains.

39At the end of two months, she returned to her father, and he kept the vow he had made about her. And she had never been intimate with a man. Now it became a custom in Israel