Moab's major transgression was the result of a long-burning feud between Moab and Edom. Out of spite and anger, the Moabites dug up the bones of a long-dead Edomite king and threw them into a fire. This is another example of taking advantage of someone who is weak and defenseless. Can a corpse fight back? The principle here is that every sin has a boomerang. God noticed the sin, burning the bones of the king of Edom, and promised to avenge it (Deuteronomy 32:35).