BSB(i)
19 When you lay siege to a city for an extended time while fighting against it to capture it, you must not destroy its trees by putting an axe to them, because you can eat their fruit. You must not cut them down. Are the trees of the field human, that you should besiege them?
20 But you may destroy the trees that you know do not produce fruit. Use them to build siege works against the city that is waging war against you, until it falls.