Deuteronomy.
Chapter 20.
When you go out to war against your enemies and see horses, chariots, and an army larger than yours, do not be afraid of them; for the LORD your God, who brought you out of the land of Egypt, is with you. 
When you are about to go into battle, the priest is to come forward and address the army, 
saying to them, “Hear, O Israel, today you are going into battle with your enemies. Do not be fainthearted or afraid; do not be alarmed or terrified because of them. 
For the LORD your God goes with you to fight for you against your enemies, to give you the victory.” 
Furthermore, the officers are to address the army, saying, “Has any man built a new house and not dedicated it? Let him return home, or he may die in battle and another man dedicate it. 
Has any man planted a vineyard and not begun to enjoy its fruit? Let him return home, or he may die in battle and another man enjoy its fruit. 
Has any man become pledged to a woman and not married her? Let him return home, or he may die in battle and another man marry her.” 
Then the officers shall speak further to the army, saying, “Is any man afraid or fainthearted? Let him return home, so that the hearts of his brothers will not melt like his own.” 
When the officers have finished addressing the army, they are to appoint commanders to lead it. 
When you approach a city to fight against it, you are to make an offer of peace. 
If they accept your offer of peace and open their gates, all the people there will become forced laborers to serve you. 
But if they refuse to make peace with you and wage war against you, lay siege to that city. 
When the LORD your God has delivered it into your hand, you must put every male to the sword. 
But the women, children, livestock, and whatever else is in the city—all its spoil—you may take as plunder, and you shall use the spoil of your enemies that the LORD your God gives you. 
This is how you are to treat all the cities that are far away from you and do not belong to the nations nearby. 
However, in the cities of the nations that the LORD your God is giving you as an inheritance, you must not leave alive anything that breathes. 
For you must devote them to complete destruction —the Hittites, Amorites, Canaanites, Perizzites, Hivites, and Jebusites—as the LORD your God has commanded you, 
so that they cannot teach you to do all the detestable things they do for their gods, and so cause you to sin against the LORD your God. 
When you lay siege to a city for an extended time while fighting against it to capture it, you must not destroy its trees by putting an axe to them, because you can eat their fruit. You must not cut them down. Are the trees of the field human, that you should besiege them? 
But you may destroy the trees that you know do not produce fruit. Use them to build siege works against the city that is waging war against you, until it falls. 
