Deuteronomy 20:13-16

13The Lord your God will give the city to you. Then you must kill all the men there.

14But you can take for yourselves the women, the children, the animals and other valuable things in the city. You can take all these things from your enemies that God gives to you.

15You must do this to all the cities that are far away from you. But it is different for the cities that belong to the nations of Canaan where you will live.

16You will take for yourselves the cities in the land that the Lord your God is giving to you as your home. In those cities, you must kill everything that is alive, people and animals.