2 Chronicles 18:3, 5, 9

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.

Therefore the king of Israel gathered together of prophets four hundred men, and said unto them, Shall we go to Ramoth-gilead to battle, or shall I forbear? And they said, Go up; for God will deliver it into the king's hand.

And the king of Israel and Jehoshaphat king of Judah sat either of them on his throne, clothed in their robes, and they sat in a void place at the entering in of the gate of Samaria; and all the prophets prophesied before them.