Judges 11:37-39

37And she said to her father, Let this thing be done for me: leave me alone two months, that I may go and descend to the mountains, and bewail my virginity, I and my companions.

38And he said, Go. And he sent her away for two months. And she went with her companions, and bewailed her virginity upon the mountains.

39And it came to pass at the end of two months, that she returned to her father, and he performed on her the vow that he had vowed; and she had known no man. And it became a fixed custom in Israel,