1 Chronicles 23:3

The Levites thirty years old and upward were counted, and their number man by man was 38,000.

1 Chronicles 23:24

These were the Levites by their fathers’ households, the heads of the fathers’ households of those registered, according to the number of names of the individuals who were the servants of the house of the Lord, from twenty years old and upward.

Numbers 4:2-49

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

Thirty and eight

Numbers 4:48
the men that were numbered were 8,580.

General references

Numbers 4:35
from thirty years and upward even to fifty years old, everyone who enters the service to do the work in the Tent of Meeting (tabernacle);