Dressed in royal attire, the king of Israel and Jehoshaphat king of Judah were sitting on their thrones at the threshing floor by the entrance of the gate of Samaria, with all the prophets prophesying before them.
This is almost word for word the same with what we had, 1 Kings 22. We will not repeat what was there said, nor have we much to add, but may take occasion to think, 1. Of the great duty of acknowledging God in all our ways and enquiring at his word, whatever we undertake. Jehoshaphat was not willing to proceed till he had done this, Ch2 18:4.
Commenting on 2 Chronicles 18:4-27
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. (h) That is, in their majesty and royal apparel.
The king of Israel and Jehoshaphat - "Ahab consulted false prophets; but Jehoshaphat sought instruction from the presence of the Lord, and prayed at the entering in of Samaria; and before these all the false prophets prophesied lies." - Targum.