Albert Barnes Commentary 1 Kings 22:10

"Now the king of Israel and Jehoshaphat the king of Judah were sitting each on his throne, arrayed in their robes, in an open place at the entrance of the gate of Samaria; and all the prophets were prophesying before them." — 1 Kings 22:10 (ASV)

Sat each on his throne - Or, “were sitting.” They had moved from the banquet (2 Chronicles 18:2) to the open area, or empty space, at the entrance of the gate (Ruth 4:1; 2 Samuel 15:2), where Ahab would daily sit to hear complaints and settle disputes. Each was seated on his throne, as Eastern kings had portable thrones that they took with them on their journeys.