Why did Aharon wave the Levi'im?
Why does the Torah mention Tenufah three times in this Parshah?
Rashi: Once regarding the B'nei K'has ? "Vehayu La'avod Avodas Hashem" (in this Pasuk); 1 Once regarding the B'nei Gershon ? "Tenufah la'Hashem" (in Pasuk 13) 2 ; And once regarding the B'nei Merari ? "Veheinafta osam Tenufah" (in Pasuk 15) 3 .
Rashbam: The Torah repeats "Veheinafta osam Tenufah" in Pasuk 15, to inform Moshe that he should wave the Levi'im after Aharon. 4
Rashi: Because they carried the holy vessels.
Rashi: Because they too, transported the curtains and the hooks, which were also Kodesh because they were visible in the Kodesh Kodshim.
Rashi: Since they carried the planks, which were not Kodesh.
Oznayim la'Torah: This was necessary due to the two types of Avodah performed by the Levi'im - 1. Avodos that only the Levi'im may perform - see Oznayim ls'Torah), into which Aharon inaugurated them; 2. Avodos that a Kohen and even a Zar are permitted to perform - such as Shechting and skinning, into which Moshe inaugurated them