Deuteronomy 20:18-19

18lest they teach you to do according to all their abominations which they have done for their gods, and you sin against the Lord your God.

19“When you besiege a city for a long time, while making war against it to take it, you shall not destroy its trees by wielding an ax against them; if you can eat of them, do not cut them down to use in the siege, for the tree of the field is man’s food.