These were the names of the sons of Gershon by their clans: Libni and Shimei.
The Levites being granted to Aaron to minister to him, they are here delivered to him by tale, that he might know what he had, and employ them accordingly. Observe, I. By what rule they were numbered: Every male from a month old and upward, Num 3:15.
Commenting on Numbers 3:14-39
And these are the names of the sons of Gershon, by their families,.... Or to Gershon belonged two families, called after the names of his sons, who were now numbered, namely: Libni and Shimei; and who are elsewhere mentioned as his sons, Exo 6:17; and from hence were the families of the Libnites and Shimites, as in Num 3:21.
Num 3:14-20 The muster of the Levites included all the males from a month old and upwards, because they were to be sanctified to Jehovah in the place of the first-born; and it was at the age of a month that the latter were either to be given up or redeemed (comp. Num 3:40 and Num 3:43 with Num 18:16).
Commenting on Numbers 3:14-20