1)
Why does it say "l'Chulam"?
1.
Malbim: Also all the Leviyim came ? all 24 Mishmaros, and the 288 heads of Mishmaros.
2)
Why did they stand in the east?
1.
Malbim: The Duchan (platform on which they sing) was in the east.
3)
Why were Kohanim with them?
1.
Malbim: Kohanim must blow the trumpets.
4)
Why were there 120 Kohanim blowing trumpets?
1.
Malbim: This is the maximum number allowed, like the Rambam says (Hilchos Klei ha'Mikdash, 3:4).
