Deuteronomy 20:14-18

14Only the women, children, livestock and all that is in the city—all its spoil—may you take as plunder for yourself. So you may consume your enemies’ spoil, which Adonai your God has given you.

15Thus you will do to all the cities that are very distant from you, which are not among the towns of these nations nearby.

16However, only from the cities of these peoples, which Adonai your God is giving you as an inheritance, you must not let anything that breathes live.

17You must utterly destroy them—the Hittites , the Amorites , the Canaanites , the Perizzites , the Hivites and the Jebusites—just as Adonai your God has commanded you.

18You are to do this so they will not teach you to do all the abominations as they have done for their gods, and so you would sin against Adonai your God.