Deuteronomy 20:16-18

New Century Version

¹⁶ But leave nothing alive in the cities of the land the Lord your God is giving you. ¹⁷ Completely destroy these people: the Hittites, Amorites, Canaanites, Perizzites, Hivites, and Jebusites, as the Lord your God has commanded. ¹⁸ Otherwise, they will teach you what they do for their gods, and if you do these hateful things, you will sin against the Lord your God.