Their listing according to the number of all the males from a month old and upward was 6,200.
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 the chief of the house of the father of the families of Merari,.... I think it should rather be rendered, "and the chief of the house", that is, of the Merarites, "the father to the families of Merari"; the common father to them all, having the chief authority and power over them, and so in Num 3:24, shall be Zuriel the son of Abihail...
Num 3:33-37 The Merarites, who formed two families, comprising 6200 males, were to encamp on the north side of the tabernacle, under their prince Zuriel, and to observe the boards, bolts, pillars, and sockets of the dwelling-place (Exo 26:15, Exo 26:26, Exo 26:32, Exo 26:37), together with all the vessels thereof (the plugs and tools), and all that had to be done in connection therewith...
Commenting on Numbers 3:33-37