מִיָּמִ֣ים ׀ יָמִ֗ימָה תֵּלַ֙כְנָה֙ בְּנ֣וֹת יִשְׂרָאֵ֔ל לְתַנּ֕וֹת לְבַת־יִפְתָּ֖ח הַגִּלְעָדִ֑י אַרְבַּ֥עַת יָמִ֖ים בַּשָּׁנָֽה׃ (ס)
that the daughters of Israel went yearly to lament the daughter of Jephthah the Gileadite four days in a year.
Read halakhic rulings (Jewish law) on Judges 11:40: and classical halakhic sources.