רַ֗ק מֵעָרֵ֤י הָֽעַמִּים֙ הָאֵ֔לֶּה אֲשֶׁר֙ יְהוָ֣ה אֱלֹהֶ֔יךָ נֹתֵ֥ן לְךָ֖ נַחֲלָ֑ה לֹ֥א תְחַיֶּ֖ה כָּל־נְשָׁמָֽה׃
Howbeit of the cities of these peoples, that the LORD thy God giveth thee for an inheritance, thou shalt save alive nothing that breatheth,
Read kabbalistic (mystical) interpretation of Deuteronomy 20:16: and classical mystical sources.