Deuteronomy 20:15-17

20:15 This is how you are to deal with all those cities located far from you, those that do not belong to these nearby nations.

Laws Concerning War with Canaanite Nations

20:16 As for the cities of these peoples that the Lord your God is going to give you as an inheritance, you must not allow a single living thing to survive. 20:17 Instead you must utterly annihilate them – the Hittites, Amorites, Canaanites, Perizzites, Hivites, and Jebusites – just as the Lord your God has commanded you,