Numbers 4:19-22 New American Bible, Revised Edition (NABRE)

19. That they may live and not die when they approach the most sacred objects, this is what you shall do for them: Aaron and his sons shall go in and assign to each of them his task and what he must carry;

20. but the Kohathites shall not go in to look upon the sacred objects even for an instant, or they will die.

21. The Lord said to Moses:

22. Take a census of the Gershonites also, by ancestral houses and clans,

Numbers 4