"You shall not destroy its trees"—Deuteronomy 20:19.
In the course of battle, while besieging an enemy city, it is forbidden to cut down fruit-bearing trees in order to cause distress and pain to the city's inhabitants.
Included in this mitzvah is the prohibition against any wanton destruction; for example, cutting down a fruit-bearing tree [even not in time of battle], or needlessly burning a garment or breaking a utensil.