Deuteronomy 20:10-18

10“When you go near a city to fight against it, then proclaim an offer of peace to it.

11And it shall be that if they accept your offer of peace, and open to you, then all the people who are found in it shall be placed under tribute to you, and serve you.

12Now if the city will not make peace with you, but makes war against you, then you shall besiege it.

13And when the Lord your God delivers it into your hands, you shall strike every male in it with the edge of the sword.

14But the women, the little ones, the livestock, and all that is in the city, all its spoil, you shall plunder for yourself; and you shall eat the enemies’ plunder which the Lord your God gives you.

15Thus you shall do to all the cities which are very far from you, which are not of the cities of these nations.

16“But of the cities of these peoples which the Lord your God gives you as an inheritance, you shall let nothing that breathes remain alive,

17but you shall utterly destroy them: the Hittite and the Amorite and the Canaanite and the Perizzite and the Hivite and the Jebusite, just as the Lord your God has commanded you,

18lest they teach you to do according to all their abominations which they have done for their gods, and you sin against the Lord your God.