Numbers 4:42-49

Also, the men in the families and family groups of the Merari family were counted, the men from thirty to fifty years old who were to work at the Meeting Tent. The family groups had 3,200 men. This was the total of the Merari family groups, whom Moses and Aaron counted as the LORD had commanded Moses. So Moses, Aaron, and the leaders of Israel counted all the Levites by families and family groups. They counted the men from thirty to fifty who were given work at the Meeting Tent and who carried the Tent. The total number of these men was 8,580. 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.