Deuteronomy 20:10-20

10When thou approachest unto a city to fight against it, thou shalt proclaim peace unto it. 11And it shall be, if it make thee answer of peace, and open unto thee, then all the people that are found therein shall be tributaries unto thee, and they shall serve thee. 12And if it will not make peace with thee, but will make war with thee, then thou shalt besiege it; 13and when Jehovah thy 1God delivereth it into thy hand, thou shalt smite every male thereof with the edge of the sword: 14only the women, and the little ones, and the cattle, and all that shall be in the city, all the spoil thereof, shalt thou take as booty for thyself; and thou shalt eat the spoil of thine enemies, which Jehovah thy 2God giveth thee 15Thus shalt thou do unto all the cities that are very far off from thee, which are not of the cities of these nations. 16But of the cities of these peoples which Jehovah thy 3God giveth thee for an inheritance, thou shalt save alive nothing that breatheth, 17but shalt utterly devote them to destruction, the Hittites and the Amorites, the Canaanites and the Perizzites, the Hivites and the Jebusites, as Jehovah thy 4God hath commanded thee; 18that they teach you not to do according to all their abominations, which they have done unto their 5gods, so that ye sin against Jehovah your 6God. 19When thou shalt besiege a city many days, in making war against it to take it, thou shalt not destroy the trees thereof by lifting up an axe against them; for thou canst eat of them; and thou shalt not cut them down, for is the tree of the field a man that it should be besieged? 20Only the trees which thou knowest are not trees for meat, thou mayest destroy and cut them down, and build bulwarks against the city that maketh war with thee, until it fall.