20 The sons of Merari by their families: Mahli and Mushi.
These are the families of the Levites according to their fathers’ houses. 21 Of Gershon was the family of the Libnites, and the family of the Shimeites: these are the families of the Gershonites. 22 Those who were numbered of them, according to the number of all the males, from a month old and upward, even those who were numbered of them were seven thousand five hundred. 23 The families of the Gershonites shall encamp behind the tabernacle westward. 24 The prince of the fathers’ house of the Gershonites shall be Eliasaph the son of Lael. 25 The duty of the sons of Gershon in the Tent of Meeting shall be the tabernacle, and the tent, its covering, and the screen for the door of the Tent of Meeting, 26 and the hangings of the court, and the screen for the door of the court, which is by the tabernacle, and around the altar, and its cords for all of its service. 27 Of Kohath was the family of the Amramites, and the family of the Izharites, and the family of the Hebronites, and the family of the Uzzielites: these are the families of the Kohathites. 28 According to the number of all the males, from a month old and upward, there were eight thousand six hundred, keeping the requirements of the sanctuary. 29 The families of the sons of Kohath shall encamp on the south side of the tabernacle. 30 The prince of the fathers’ house of the families of the Kohathites shall be Elizaphan the son of Uzziel. 31 Their duty shall be the ark, the table, the lamp stand, the altars, the vessels of the sanctuary with which they minister, and the screen, and all its service. 32 Eleazar the son of Aaron the priest shall be prince of the princes of the Levites, with the oversight of those who keep the requirements of the sanctuary. 33 Of Merari was the family of the Mahlites, and the family of the Mushites. These are the families of Merari. 34 Those who were numbered of them, according to the number of all the males, from a month old and upward, were six thousand two hundred. 35 The prince of the fathers’ house of the families of Merari was Zuriel the son of Abihail. They shall encamp on the north side of the tabernacle.
Matthew Henry's Commentary on Numbers 3:20-35
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.