Treasury of Scripture Knowledge
from thirty years old and upward to fifty years old, all who enter the company to do the work in the tent of meeting.
"This is what pertains to the Levites: At the age of twenty-five years and upward one may begin to join the company in the work of the tent of meeting,
1 Chronicles 23:3
The Levites who were thirty years old and up were counted; there were 38,000 men.
1 Chronicles 28:13
He gave him the regulations for the divisions of priests and Levites, for all the assigned responsibilities within the Lord's temple, and for all the items used in the service of the Lord's temple.
So Jesus, when he began his ministry, was about thirty years old. He was the son (as was supposed) of Joseph, the son of Heli,
1 Timothy 3:6
He must not be a recent convert or he may become arrogant and fall into the punishment that the devil will exact.