2 Kings 3:19

This is either, first, A command; and then the last clause is an exception from that law, Deuteronomy 20:19, which being delivered by a prophet, might be obeyed. And if this command seem severe, it must be considered that the Moabites were a very wicked people, perfidious, cruel, implacable enemies to God's people upon all occasions, and now in a state of rebellion. Or rather, secondly, A prediction of their success, that they should have so full and complete a victory, that they should be able to do all which is here expressed.