Numbers 8:25

but from the age of fifty years, shall they retire from taking rank in the labour, and shall do laborious work no more;

Numbers 4:23

from thirty years old and upwards even to fifty years, shalt thou number them, - All that may enter to take rank in the host, to do laborious work in the tent of meeting.

2 Timothy 4:7

The noble contest, have I contested, the race, have I finished, the faith, have I kept:

Treasury of Scripture Knowledge

Summary

And from the age of fifty years they shall cease waiting upon the service thereof, and shall serve no more:

General references

Bible References

General references

Numbers 4:35
from thirty years old and upwards, even unto fifty years old, all that might enter the host, to labour in the tent of meeting;