Number the children of Levi after the house of their fathers, by their families: every male from a month old and upward shalt thou number them.
15. Number the children of Levi after the house of their fathers The enumeration of the tribe now follows, commencing with the three sons of Levi, Kohath, Gershon, and Merari, from whom many families afterwards descended. It must, however, be observed, that all were numbered down to the youngest infants, whereas of the rest of the people only those who had passed their twentieth year...
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
Number the children of Levi,.... Who were left out of the general muster of the children of Israel, but now were to be numbered alone, and in a different manner, and for, a different purpose, the Lord having a special regard auto, them, and special service for them: after the house of their fathers, by their families; into which the tribe was divided; house seems...