The document discusses why the Torah lists four examples of things that can be burned by a fire in a particular verse: thorns, a stack of grain, standing grain, and a field. Each additional term is meant to extend the liability of the person who started the fire. If only thorns were mentioned, one might think they are the only thing liable for. If only grain was mentioned, one might think only substantial losses are liable for, not minor ones like thorns. By listing all four terms, the full extent of liability is learned.