Deuteronomy 20:16

13 And when the Lord your God has given it into your hands, let every male in it be put to death without mercy.

14 But the women and the children and the cattle and everything in the town and all its wealth, you may take for yourselves: the wealth of your haters, which the Lord your God has given you, will be your food.

15 So you are to do to all the towns far away, which are not the towns of these nations.

16 But in the towns of these peoples whose land the Lord your God is giving you for your heritage, let no living thing be kept from death:

17 Give them up to the curse; the Hittite, the Amorite, the Canaanite, the Perizzite, the Hivite, and the Jebusite, as the Lord your God has given you orders:

18 So that you may not take them as your example and do all the disgusting things which they do in the worship of their gods, so sinning against the Lord your God.

19 If in war a town is shut in by your armies for a long time, do not let its trees be cut down and made waste; for their fruit will be your food; are the trees of the countryside men for you to take up arms against them?