Why does it say "Ein Lahem Lasur"?
Metzudas David: The singers 1 and gatekeepers did not need to abandon their Avodah, for the other Leviyim 2 prepared their Pesachim.
Malbim: The singers and gatekeepers could not abandon their Avodah, therefore other Leviyim needed to prepare their Pesachim.
Ralbag: This teaches that Leviyim sing when Pesach is offered. The Torah taught only at the time that Olah and Shelamim are offered.
'Rashi' (Divrei ha'Yamim I, 1:1): David divided the Leviyim into gatekeepers, guards and singers. (All other Meforshim imply that there are only singers and gatekeepers. They could explain that 'other Leviyim' are too young to serve, or did not yet learn Hilchos Avodah. (PF)
To whom does "Choze ha'Melech" apply?
'Rashi': It applies to each of them (Asaf, Heiman and Yedusun).
