וְהָיָה֙ אִם־שָׁל֣וֹם תַּֽעַנְךָ֔ וּפָתְחָ֖ה לָ֑ךְ וְהָיָ֞ה כָּל־הָעָ֣ם הַנִּמְצָא־בָ֗הּ יִהְי֥וּ לְךָ֛ לָמַ֖ס וַעֲבָדֽוּךָ׃
And it shall be, if it make thee answer of peace, and open unto thee, then it shall be, that all the people that are found therein shall become tributary unto thee, and shall serve thee.
Read kabbalistic (mystical) interpretation of Deuteronomy 20:11: and classical mystical sources.