Numbers 4:30

From thirty years old and upward
The Septuagint version here, and in ( Numbers 4:3 Numbers 4:23 ) , renders it, from twenty five years old and upward, agreeable to ( Numbers 8:24 ) , at the which age the Levites went into the tabernacle, to wait and to learn their business, but they did not enter upon it till thirty;

even unto fifty years old shalt thou number them;
at which age they were discharged from business:

everyone that entereth into the service, to do the work of the
tabernacle of the congregation; (See Gill on Numbers 4:3).