In the pavilions - This word comes from papilio, a butterfly, because tents, when pitched or spread out, resembled such animals; partly because of the mode of their expansion, and partly because of the manner in which they were painted.
Set yourselves in array - The original word, שימו simu, which we translate by this long periphrasis, is probably a military term for Begin the attack, Invest the city, Every man to his post, or some such like expression.
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.