2 Chronicles 18:4-6
18:4 Then Jehoshaphat added, “First seek an oracle from the Lord.”
18:5 So the king of Israel assembled 400 prophets and asked them, “Should we attack Ramoth Gilead or not?” They said, “Attack! God will hand it over to the king.”
18:6 But Jehoshaphat asked, “Is there not a prophet of the Lord still here, that we may ask him?”