2 Kings 3:5-8

5But after Ahab’s death, the king of Moab rebelled against the king of Israel.

6So King Joram promptly mustered the army of Israel and marched from Samaria.

7On the way, he sent this message to King Jehoshaphat of Judah: “The king of Moab has rebelled against me. Will you join me in battle against him?” And Jehoshaphat replied, “Why, of course! You and I are as one. My troops are your troops, and my horses are your horses.”

8Then Jehoshaphat asked, “What route will we take?” “We will attack from the wilderness of Edom,” Joram replied.