2 Chronicles 18:1-3

Now Jehoshaphat had riches and honour in abundance, and joined affinity with Ahab. And after certain years he went down to Ahab to Samaria. And Ahab killed sheep and oxen for him in abundance, and for the people that he had with him, and persuaded him to go up with him to Ramoth-gilead. And Ahab king of Israel said unto Jehoshaphat king of Judah, Wilt thou go with me to Ramoth-gilead? And he answered him, I am as thou art, and my people as thy people; and we will be with thee in the war.