Seeing as the bull came to atone for Aharon for the sin of the Golden Calf, why did his sons need to lean their hands on it?
R. Bachye (in Pasuk 14): Because Hakadosh-Baruch-Hu, in His anger, wanted to punish Ahron by killing his sons, so they too needed to attain a Kaparah through it.
Why here does the Torah wrie "Vesamchu Aharon u'Vanav" whereas regarding the bull and the second ram, it writes "Vesamach Aharon u'Vanav"?
Da'as Zekenim: Perhaps here they all did Semichah together 1 , whereas regarding the bull and the second ram, first Aharon did Semichah, and afterwards his sons; or perhaps "Aharon" is written with a 'Vav' 2 , to add the 'Vav' to 'Vesamach' of the others, to read 'Vesamchu' - to each us tha hey all performed Semichah together.
Semichah must be performed with all ones's strength. How could five men fit their hands on a ram's head to lean with all their strength? He Gemara sates in Menachos 94a (for Tenufah) that if one places one's hands on someone else's hands, it is a Chatzitzah! (Perhaps the Yerushalmi argues - Tosfos Menachos 61b DH Kohen.) And how could the ram's head bear all that pressure? Perhaps it was a miracle (PF).
Minchas Shai: In accurate manuscripts and old printings, there is no Vav. (Our Seforim do not have a Vav - PF.)
