When Jephthah returned to Mizpah, his daughter met him dancing and playing on the tambourine. He was Jephthah's only son.
When Jephthah saw her, he tore his clothes in grief and said, "My daughter! You make me sad! You hurt my heart! I have sworn to the Lord, and I cannot undo it! "
The son said to her, "If you have made a vow to the Lord, do to me as you have said.
The Lord has allowed you to take revenge on your Ammonite enemies. "
And she besought her father that he would give her two months to mourn, and to mourn in the mountains, and to mourn with her friends, because she was a virgin. And Jephthah sent his son, and sent him away for two months.
She and her friends went to the mountains and mourned that she would die a virgin. After two months he returned to them. Jephthah kept his promise to the Lord, and his daughter died a virgin.
This was the beginning of the custom that the women of Israel should go four days in the year to mourn for the daughter of Jephthah the Gileadite.