These were counted from the Kohathite clans, everyone who could serve at the Tent of Meeting. Moses and Aaron numbered them according to the command of the LORD through Moses.
KJV
These [were] they that were numbered of the families of the Kohathites, all that might do service in the tabernacle of the congregation, which Moses and Aaron did number according to the commandment of the LORD by the hand of Moses.
ASV
These are they that were numbered of the families of the Kohathites, all that did serve in the tent of meeting, whom Moses and Aaron numbered according to the commandment of Jehovah by Moses.
everyone from thirty to fifty years old who came to serve in the work at the Tent of Meeting.
KJV
From thirty years old and upward even unto fifty years old, every one that entereth into the service, for the work in the tabernacle of the congregation,
ASV
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,