2 Chronicles 18:2-3

2After some years, he went to visit Ahab in Samaria. Ahab killed many sheep and cows to give honour to Jehoshaphat and the people who were with him. Ahab wanted to attack Ramoth Gilead, so he asked Jehoshaphat to help him.

3King Ahab of Israel said to King Jehoshaphat of Judah, ‘Will you go with me to attack Ramoth Gilead?’ Jehoshaphat replied, ‘Yes, we should work together! Use my soldiers as if they belonged to you. My army will join with your army in the war.’