Deuteronomy 20:18-20

New Revised Standard Version Catholic Edition

¹⁸ so that they may not teach you to do all the abhorrent things that they do for their gods, and you thus sin against the Lord your God.

¹⁹ If you besiege a town for a long time, making war against it in order to take it, you must not destroy its trees by wielding an ax against them. Although you may take food from them, you must not cut them down. Are trees in the field human beings that they should come under siege from you? ²⁰ You may destroy only the trees that you know do not produce food; you may cut them down for use in building siegeworks against the town that makes war with you, until it falls.