The families from the tribe of Levi were not listed with the others, because
But Joab did not count the tribes of Levi and Benjamin, because he didn’t like King David’s order.
You and Aaron must count every man twenty years old or older who will serve in the army of Israel, and list them by their divisions.
the Lord had told Moses:
Instead put the Levites in charge of the Holy Tent of the Agreement and everything that is with it. They must carry the Holy Tent and everything in it, and they must take care of it and make their camp around it.
Moses obeyed the Lord and did not count the Levites among the other people of Israel.
This is the family history of Aaron and Moses at the time the Lord talked to Moses on Mount Sinai.
The Lord again said to Moses in the Desert of Sinai,
“Count the Levites by families and family groups. Count every male one month old or older.”
Each man was counted as the Lord had commanded Moses; each man was given his work and told what to carry as the Lord had commanded Moses.