Midrasch zu Könige I 22:10

CHULIN (Fol. 5) (I Kings 22, 10) Now the king of Israel and Jehosaphat the king of Judah sat each on his throne, arrayed in their robes, in the threshing-floor, at the entrance of the gate of Samaria. What does 'in the threshing-floor' mean? Was then the gate of Samaria a threshing-floor? We must therefore say that they were sitting in a position similar to the shape of a threshing-floor (in a semi-circle); for we are taught in a Mishna that the Sanhedrin sat in a semi-circle in the shape of a threshing-floor so that they should be able to see one another. (Ib. 17, 6) And the ravens brought him bread and flesh in the morning, and bread and flesh in the evening. Said R. Juda in the name of Rab: "They brought it from King Achab's butchers upon a Divine order." What is the meaning of 'ravens'? Said Rabina: "Real ravens."

... R’ Bibi and R’ Reuven said in the name of R’ Chanina: in the future the Holy One will appoint a yeshiva for His elders. This is what is written “…for the Lord of Hosts has reigned in Mount Zion…” the end of the verse is not written ‘and before elders will be glory’ but rather “…and before His elders will be glory.” (Isaiah 24:23)

It was customary for kings to preside in a circular courtroom, as it says: And now the king of Israel and Jehoshaphat the king of Judah sat each on his throne, arrayed in their robes, in a threshing floor (I Kings 22:10). Did they actually sit on a threshing floor? No. We have learned that the Sanhedrin met in a semicircle, in order that each member might be able to see the others, while the two scribes sat before them to write down the testimony. Solomon said: I see him sitting with them and judging in their midst, as it is said: Her husband is known in the gates, when he sitteth among the elders of the land (Prov. 31:23).