38 Moses and Aaron and his sons camped to the east of The Dwelling, toward the rising sun, in front of the Tent of Meeting. They were in charge of maintaining the Sanctuary for the People of Israel and the rituals of worship. Anyone else who tried to perform these duties was to be put to death.
Matthew Henry's Commentary on Numbers 3:38
Commentary on Numbers 3:14-39
(Read Numbers 3:14-39)
The Levites were in three classes, according to the sons of Levi; Gershon, Kohath, and Merari; and these were subdivided into families. The posterity of Moses were not at all honoured or privileged, but stood upon the level with other Levites; thus it was plain, that Moses did not seek the advancement of his own family, or to secure any honours to it. The tribe of Levi was by much the least of all the tribes. God's chosen are but a little flock in comparison with the world.