1)
What is the definition of the words "La'avod" and "le'Masa", respectively?
1.
Seforno: "La'avod" refers to what they were in charge of whilst they were encamped and "le'Masa", what they were in charge of when they traveled. 1
1
Seforno: In fact, the Torah is teaching us here, that whatever the B'nei Gershon were in charge of when they encamped ? as stated in Bamidbar 3:25, they were also in charge of when they traveled.