2 Kings 3:6-8

3:6 At that time King Jehoram left Samaria and assembled all Israel for war. 3:7 He sent this message to King Jehoshaphat of Judah: “The king of Moab has rebelled against me. Will you fight with me against Moab?” Jehoshaphat replied, “I will join you in the campaign; my army and horses are at your disposal.” 3:8 He then asked, “Which invasion route are we going to take?” Jehoram answered, “By the road through the Desert of Edom.”