Judges 11:40

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

³⁹  And it came to pass at the end of two months, that she returned unto her father, who did with her according to his vow which he had vowed: and she knew no man. And it was a custom in Israel,

⁴⁰  That the daughters of Israel went yearly to lament the daughter of Jephthah the Gileadite four days in a year.