Deuteronomy 20:16-18

Amplified Bible

¹⁶ Only in the cities of these peoples that the Lord your God is giving you as an inheritance, you shall not leave alive anything that breathes. ¹⁷ But you shall utterly destroy them, the Hittite, the Amorite, the Canaanite, the Perizzite, the Hivite and the Jebusite, just as the Lord your God has commanded you, ¹⁸ so that they will not teach you to act in accordance with all the detestable practices which they have done [in worship and service] for their gods, and in this way cause you to sin against the Lord your God.