1 Chronicles 23:3

The Levites were numbered from thirty years old and upward, and their number by census of men was 38,000.

1 Chronicles 23:24

These were the sons of Levi according to their fathers’ households, even the heads of the fathers’ households of those of them who were counted, in the number of names by their census, doing the work for the service of the house of the Lord, from twenty years old and upward.

Numbers 4:2-49

“Take a census of the descendants of Kohath from among the sons of Levi, by their families, by their fathers’ households,

Treasury of Scripture Knowledge

Summary

Now the Levites were numbered from the age of thirty years and upward: and their number by their polls, man by man, was thirty and eight thousand.

The levites

Thirty and eight

General references

Bible References

The levites

Numbers 4:2
“Take a census of the descendants of Kohath from among the sons of Levi, by their families, by their fathers’ households,

Thirty and eight

Numbers 4:48
Their numbered men were 8,580.

General references

Numbers 4:35
from thirty years and upward even to fifty years old, everyone who entered the service for work in the tent of meeting.