from thirty years old and upward to fifty years old, everyone who entered to do the work of service and the work of carrying relating to the tent of meeting –

“When Aaron and his sons have finished covering the sanctuary and all the furnishings of the sanctuary, when the camp is ready to journey, then the Kohathites will come to carry them; but they must not touch any holy thing, or they will die. These are the responsibilities of the Kohathites with the tent of meeting.

And Moses said to the Lord, “Why have you afflicted your servant? Why have I not found favor in your sight, that you lay the burden of this entire people on me?