TSK · Numbers 4:35

from thirty years old and upward until fifty years old shalt thou number them; all that enter in to wait upon the service, to do the work in the tent of meeting.

from thirty years old and upward even unto fifty years old, every one that entered upon the service, for work in the tent of meeting,

from thirty years old and upward even unto fifty years old, every one that entered in to do the work of service, and the work of bearing burdens in the tent of meeting,

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

and also the Levites shall no more have need to carry the tabernacle and all the vessels of it for the service thereof.

And Jesus himself, when he began [to teach], was about thirty years of age, being the son (as was supposed) of Joseph, the [son] of Heli,