1)
Why does the Torah write "Kol ha'Ba" regarding Gershon and Merari, and regarding K'has, "Kol Ba"?
1.
Moshav Zekeinim (in Pasuk 22): The 'Hey' teaches us that they came immediately and dismantled the Mishkan, whereas the B'nei K'has were not allowed to come until after Aharon and his sons had covered the K'lei Kodesh.
2)
Why does the Torah write "La'avod Avodah" regarding Gershon and Merari, and "La'asos Melachah" regarding K'has?
1.
Moshav Zekeinim (in Pasuk 22): Gershon and Merari did hard work, to dismantle and assemble the Mishkan, whereas K'has only carried it.
