17 And the Lord said to Moses and Aaron,
18 [Since] the tribe of the families of the Kohathites [are only Levites and not priests], do not [by exposing them to the sin of touching the most holy things] cut them off from among the Levites.
19 But deal thus with them, that they may live and not die when they approach the most holy things: Aaron and his sons shall go in and appoint them each to his work and to his burden [to be carried on the march].
20 But [the Kohathites] shall not go in to see the sanctuary [the Holy Place and the Holy of Holies] or its holy things, even for an instant, lest they die.
21 And the Lord said to Moses,
22 Take a census of the sons of Gershon, by their fathers' houses, by their families.
23 From thirty years old and up to fifty years old you shall number them, all who enter for service to do the work in the Tent of Meeting.