Judges 11:39-40 English Standard Version (ESV)

39. And at the end of two months, she returned to her father, who did with her according to his vow that he had made. She had never known a man, and it became a custom in Israel

40. that the daughters of Israel went year by year to lament the daughter of Jephthah the Gileadite four days in the year.

Judges 11