Why does the Torah here write "Aharon u'Vanav" (in the plural) whereas in the following Pasuk it mentions only Isamar"?
Rashi: Pasuk 28 explains Pasuk 27, as if to say 'which of the sons? Isamar'. 1
Ramban and Moshav Zekeinim: The current Pasuk is referring to Aharon and his sons, who appointed every ben Gershon 2 to his specific task, 3 including whether he would sing or whether he would stand guard. Also when they traveled, they did not dismantle or load on to the wagons, until they received the go-ahead from Aharon and his sons. When they returned the Keilim after traveling, however, each one handed it to Isamar who was the officer in charge of Gershon and Merari, and declared 'Here are the Keilim that were placed in my charge!'
Oznayim la'Torah: Whereas Aharon and his sons arranged the various issues concerning the Levi'im whilst the camp was still in its place, Isamar who travelled with the B'nei Gershon and the B'nei Merari, 4 was in charge of organizing the rotating groups 5 whilst they travelled,
What is the difference between "le'Chol Masa'am" and "le'Chol Avodasam"?
Seforno: "le'Chol Masa'am" refers to when they travelled, and "le'Chol Avodasam" to when they were still in the camp.
Oznayim la'Torah: "le'Chol Masa'am" refers to the carrying, and "le'Chol Avodasam" to all other areas of the Levi'im's Avodah. 1
Having written " ... Kol Avodas B'nei ha'Gershuni le'Chol Masa'am u'le'Chol Avodasam", why does the Torah mention only "Masa'am" at the end of the Pasuk?
Oznayim la'Torah: Because when it came to the carrying, it was impossible for all twenty-two thousand Levi'im to serve at the same time and it was imperative to arrange for them to carry in groups in rotation, which was not nesessarily the case with regard to the guarding and the singing. 1
See Oznayim la'Torah, who elaborates at lehgth.
