2 Chronicles 18:1-3

Now Jehoshaphat had great riches and honor; and he allied himself by marriage with Ahab. Some years later he went down to visit Ahab at Samaria. And Ahab slaughtered many sheep and oxen for him and the people who were with him, and induced him to go up against Ramoth-gilead. Ahab king of Israel said to Jehoshaphat king of Judah, “Will you go with me against Ramoth-gilead?” And he said to him, “I am as you are, and my people as your people, and we will be with you in the battle.”