כֵּ֤ן תַּעֲשֶׂה֙ לְכָל־הֶ֣עָרִ֔ים הָרְחֹקֹ֥ת מִמְּךָ֖ מְאֹ֑ד אֲשֶׁ֛ר לֹא־מֵעָרֵ֥י הַגּֽוֹיִם־הָאֵ֖לֶּה הֵֽנָּה׃
Thus shalt thou do unto all the cities which are very far off from thee, which are not of the cities of these nations.
Read halakhic rulings (Jewish law) on Deuteronomy 20:15: and classical halakhic sources.