TSK · Numbers 4:47

"When Aaron and his sons have finished covering the sanctuary, and all the furniture of the sanctuary, as the camp moves forward; after that, the sons of Kohath shall come to carry it: but they shall not touch the sanctuary, lest they die. These things are the burden of the sons of Kohath in the Tent of Meeting.

you shall count them from thirty years old and upward even to fifty years old, everyone who enters on the service, to do the work of the Tent of Meeting.

The Levites were numbered from thirty years old and upward: and their number by their polls, man by man, was thirty-eight thousand.

Having gifts differing according to the grace that was given to us, if prophecy, let us prophesy according to the proportion of our faith;