What exactly, are Aharon and his sons being instructed to do?
Rashi (in Bereishis Rabah, 23:3): The current two Pesukim, are referring to the Avodah of the Levi'im in general - that Aharon and his sons (Elazar and Isamar) should designate every Levi to his specific task, with regard to which ben Levi should sing and which ben Levi should play an instrument. 1
Rashi (Ibid.): Because a ben Levi who performs a task to which he has not been designated, is Chayav Misah bi'Yedei Shamayim, as the next Pasuk states
With reference to the Avodah of the tribe of Levi, not specifically to the B'nei K'has or even to the covering of the holy vessels. And it meant that each Levi should wait to perform the task that he had been instructed when his turn arrived.
What are the implications of "Ish Ish al Avodaso ... "?
