Deuteronomy 20:10-20

10Before you start to attack a city, you must offer peace to the people who live there. Tell them what they must do to stop you attacking them.

11If they agree, they will open the city's gates to let you go in. Then all the people in the city will become your slaves, to do hard work for you.

12But they may refuse to agree. They may start to fight against you. If they do that, you must put your soldiers all around the city.

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.

17You must completely destroy all the Hittites, the Amorites, the Canaanites, the Perizzites, the Hivites and the Jebusites. The Lord your God has commanded you to do this to the people of those nations.

18If not, they would teach you all the evil things that they do to worship their gods. They would cause you to do bad things against the Lord your God.

19Perhaps you are preparing to attack a city. Your soldiers may have their camp around the city for a long time. If so, you must not cut down the fruit trees. Then you can eat the fruit from them. These trees are not people, like your enemies! So do not attack them!

20But you can cut down the other trees that do not provide any food. You can use the wood to make things that will help you to attack the city. You can do this until you go into the city and you take it for yourselves.