Deuteronomy 20:16-18

New Catholic Bible

¹⁶ But in these cities that the Lord, your God, is giving you as an inheritance, you are not to leave anything alive. ¹⁷ Wipe them out, the Hittites, the Amorites, the Canaanites, the Perizzites, the Hivites, and the Jebusites, just as the Lord, your God, has commanded you. ¹⁸ Otherwise they will teach you to perform the abominations that they practice when they worship their gods, and you would be sinning against the Lord, your God.