Also, remember that when Ahab died, Moab rebelled against Israel. They had been in subjection to Israel and had to pay tribute, or taxes to Israel, and they were through with that.
So now, in chapter 3, we see Ahaziah’s brother, Jehoram take the throne. He also did evil in the Lord’s eyes, but not like his father Ahab or his mother Jezebel. He put away the pillar of Baal that his father had made (though he did not destroy it). He did, however, worship the calves that had been the sin of Jeroboam.
Now the Moabite king was due to pay his tribute to Jehoram, king of Israel. He was obligated to deliver 100,000 lambs and the wool of 100,000 rams. That, my friend, is a huge payment and probably meant a lot to the economy of Israel. But since the death of Ahab, two years before, the Moabite king has rebelled, and not paid.
So that’s the background on who the people are in the story and why the battle was fought. You heard how Elisha was brought in, and how the plan given by the Lord set the Moabite king to flight.
At the end of the chapter, we heard what a demonic god the Moabites had. In order to try to win the favor of his god, Chemosh, this Moabite king offered his eldest son, who was to inherit his throne, as a burnt offering. It’s no wonder that God had long since called for their destruction.