וְאֵ֤ת כָּל־עָרֵיהֶם֙ בְּמ֣וֹשְׁבֹתָ֔ם וְאֵ֖ת כָּל־טִֽירֹתָ֑ם שָׂרְפ֖וּ בָּאֵֽשׁ׃
And all their cities in the places wherein they dwelt, and all their encampments, they burnt with fire.
Read halakhic rulings (Jewish law) on Numbers 31:10: and classical halakhic sources.