Albert Barnes Commentary 1 Kings 20:12

"And it came to pass, when [Ben-hadad] heard this message, as he was drinking, he and the kings, in the pavilions, that he said unto his servants, Set [yourselves in array]. And they set [themselves in array] against the city." — 1 Kings 20:12 (ASV)

Pavilions - “Booths” (Genesis 33:17 (margin); Leviticus 23:42; Jonah 4:5). The term seems to be properly applied to a stationary “booth” or “hut,” as distinguished from a moveable “tent.” On military expeditions, and especially in the case of a siege, such “huts” were naturally constructed to shelter the king and his chief officers.