Judges 11:37-39

Good News Translation

³⁷ But she asked her father, “Do this one thing for me. Leave me alone for two months, so that I can go with my friends to wander in the mountains and grieve that I must die a virgin.” ³⁸ He told her to go and sent her away for two months. She and her friends went up into the mountains and grieved because she was going to die unmarried and childless. ³⁹ After two months she came back to her father. He did what he had promised the Lord, and she died still a virgin.

This was the origin of the custom in Israel