void...: or, floor

Geneva Study Bible

And the king of Israel and Jehoshaphat king of Judah sat either of them on his throne, clothed in their {h} 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.2 Chronicles 18:9 Parallel Commentaries

The Assyrian Revival and the Struggle for Syria
Assur-nazir-pal (885-860) and Shalmaneser III. (860-825)--The kingdom of Urartu and its conquering princes: Menuas and Argistis. Assyria was the first to reappear on the scene of action. Less hampered by an ancient past than Egypt and Chaldaea, she was the sooner able to recover her strength after any disastrous crisis, and to assume again the offensive along the whole of her frontier line. Image Drawn by Faucher-Gudin, from a bas-relief at Koyunjik of the time of Sennacherib. The initial cut, …
G. Maspero—History Of Egypt, Chaldaea, Syria, Babylonia, and Assyria, V 7

Chronicles
The comparative indifference with which Chronicles is regarded in modern times by all but professional scholars seems to have been shared by the ancient Jewish church. Though written by the same hand as wrote Ezra-Nehemiah, and forming, together with these books, a continuous history of Judah, it is placed after them in the Hebrew Bible, of which it forms the concluding book; and this no doubt points to the fact that it attained canonical distinction later than they. Nor is this unnatural. The book …
John Edgar McFadyen—Introduction to the Old Testament