Numbers 4:3

“From thirty years old and upward even until fifty years old, etc.] 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 f22, “a son of thirty years for strength,” upon which one of the commentators f23 makes this remark, that the Levites set up the tabernacle and took it down, and loaded the wagons, and carried on their shoulders from thirty years and upwards: thus both John the Baptist, the forerunner of Christ, and Christ himself, entered into their ministry at this age: all that enter into the host; army or warfare; for though the…”

“From thirty - This age was prescribed, as the age of full strength of body, and therefore most proper for their laborious work of carrying the parts and vessels of the tabernacle, and of maturity of judgment, which is necessary for the right management of holy services. Whence even John and Christ entered not upon their ministry till that age. Indeed their first entrance upon their work was at their 25th year, when they began as learners, and acted under the inspection and direction of their brethren; but in their 30th year they were compleatly admitted to a full discharge of their whole office. But David, being a prophet, and particularly directed by God in the affairs of the temple, made a…”

“4:3 Of the 22,000 Levites (3:39), only men between the ages of thirty and fifty, those in the prime of their life, were allowed to serve in the sanctuary. The summary of this registration (another “numbering”) found in 4:34-49 gives the total number of qualified males as 8,580.”

“thirty years: Num 8:24-26; Gen 41:46; Ch1 23:3, Ch1 23:24-27, Ch1 28:12, Ch1 28:13; Luk 3:23; Ti1 3:6 enter: Kg2 11:4-12; Ch2 23:1-11; Co2 10:3, Co2 10:4; Eph 6:10-18; Ti1 1:18 to do: Num 3:7, Num 3:8, Num 16:9; Ch1 6:48, Ch1 23:4, Ch1 23:5, Ch1 23:28-32; Ti1 3:1 Numbers 4:4”