Ye shall smite, &c. If this command seem severe, it must be considered that the Moabites were a very wicked people, perfidious, cruel, and implacable enemies to God's people upon all occasions, and now in a state of rebellion. But these words are rather to be considered as a prediction of their success, than as a command, enjoining them to do all these things; and thus understood, they imply that their victory should be so full and complete, that they should have it in their power to lay the country of the Moabites waste with fire and sword.
Related Commentaries of 2 Kings 3:19
2 Kings 3:19
19 And ye shall smite every fenced city, and every choice city, and shall fell every good tree, and stop all wells of water, and marb every good piece of land with stones.