Numbers 4:21

¹⁹This do ye to them, and they shall live and not die, when they approach the holy of holies: Let Aaron and his sons advance, and they shall place them each in his post for bearing.

²⁰And so they shall by no means go in to look suddenly upon the holy things, and die.

— Numbers 4:21 —

²²Take the sum of the children of Gershon, and these according to the houses of their lineage, according to their families.

²³Take the number of them from five and twenty years old and upward until the age of fifty, every one that goes in to minister, to do his business in the tabernacle of witness.