"al-Pi Hashem Pakad osam Moshe. Why does the Torah only use the term "al-Pi Hashem" when counting the Levi'im, but not when counting Yisrael?
What is the meaning of "u'Fekudav asher Tzivah Hashem es Moshe"?
Rashi, Ramban #1, Targum Onkelos and Targum Yonasan 1 : It means that the ages that Moshe counted were just as Hashem had commanded him, 2 not less than thirty and not more than fifty.
Ramban #2 (citing the Ibn Ezra): It refers to all the members of Gershon, K'has and Merari - to which "Ish Ish" is referring, and all of whom Moshe appointed by name and designated to their posts. 3
Seforno: It means that Moshe instructed each of the B'nei Merari as to which Keilim he was in charge, both when they encamped and when they traveled, as well as to the name and weight of the Keilim. 4
See Ramban, who has a different text in Rashi.
Ramban: As if it had written "Ka'asher" (with a 'Kaf').
As the Ramban explained in Bamidbar. Refer to 4:32:3:1**. No ben Levi was permitted to perform a Melachah to which he was not designated. In fact the Sifri relates an episode where R. Yehoshua ben Chananyah, who was a singer, went to assist R. Yochanan ben Gudgodah to shut the gates, and the latter stopped him - because a singer who opens or shuts the gates is Chayav Misah (bi'Yedei Shamayim).
Seforno: As the Torah indicated earlier in Pasuk 32.
