From thirty years old, &c.— The service of the ministry, &c. is, in the Hebrew, the service of service, and the service of the burden; by which seems to be meant the most laborious service, even that of the burden. The Levites appointed to this office were,
Of the Kohathites 2750
Gershonites 2630
Merarites 3200
In all 8580 all of whom Moses, with the assistance of Aaron, and the chiefs of the tribe, registered in a methodical manner; appointing to every one his particular station and employment, pursuant to the directions given of God.