from thirty years old up to fifty years old, all who can come on duty, to do the work in the tent of meeting.
We have here a second muster of the tribe of Levi. As that tribe was taken out of all Israel to be God's peculiar, so the middle-aged men of that tribe were taken from among the rest to be actually employed in the service of the tabernacle. Now observe, I. Who were to be taken into this number. All the males from thirty years old to fifty.
Commenting on Numbers 4:1-20
From thirty years old and upward even until fifty years old,.... This is the full time of the Levites service, and the prime season of man's life for business; at thirty years of age he is at his full strength, and when fifty it begins to decline: it is said in the Misnah (x),"a son of thirty years for strength,''upon which one of the commentators...
From thirty years old and upward even until fifty years old, all that enter into the host, to do the work in the tabernacle of the congregation. (a) The Levites were counted at three times, first at a month old when they were consecrated to the Lord, next at 25 years old when they were appointed to serve in the tabernacle, and 30 years old...