Judges 11:39-40

Darby Translation

³⁹ And 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,

⁴⁰ that from year to year the daughters of Israel go to celebrate the daughter of Jephthah the Gileadite four days in the year.