2 Chronicles 18:1-4

Now Jehoshaphat had great wealth and honour, and he allied himself with Ahab by marriage. Some years later he went down to see Ahab in Samaria. Ahab slaughtered many sheep and cattle for him and the people with him and urged him to attack Ramoth Gilead. Ahab king of Israel asked Jehoshaphat king of Judah, ‘Will you go with me against Ramoth Gilead?’ Jehoshaphat replied, ‘I am as you are, and my people as your people; we will join you in the war.’ But Jehoshaphat also said to the king of Israel, ‘First seek the counsel of the LORD.’