בַּת־עַמִּ֤י חִגְרִי־שָׂק֙ וְהִתְפַּלְּשִׁ֣י בָאֵ֔פֶר אֵ֤בֶל יָחִיד֙ עֲשִׂ֣י לָ֔ךְ מִסְפַּ֖ד תַּמְרוּרִ֑ים כִּ֣י פִתְאֹ֔ם יָבֹ֥א הַשֹּׁדֵ֖ד עָלֵֽינוּ׃
O daughter of my people, gird thee with sackcloth, And wallow thyself in ashes; Make thee mourning, as for an only son, Most bitter lamentation; For the spoiler shall suddenly come upon us.
Read halakhic rulings (Jewish law) on Jeremiah 6:26: and classical halakhic sources.