2 Kings 3:5-7 (KJV)
5 But it came to pass, when Ahab was dead, that the king of Moab rebelled against the king of Israel.
6 And king Jehoram went out of Samaria the same time, and numbered all Israel.
7 And he went and sent to Jehoshaphat the king of Judah, saying, The king of Moab hath rebelled against me: wilt thou go with me against Moab to battle? And he said, I will go up: I am as thou art, my people as thy people, and my horses as thy horses.