Numbers 4:42-45

Those of the families of the sons of Merari who were numbered, by their families, by their fathers’ house, from thirty years old and above, even to fifty years old, everyone who entered the service for work in the tabernacle of meeting— those who were numbered by their families were three thousand two hundred. These are the ones who were numbered of the families of the sons of Merari, whom Moses and Aaron numbered according to the word of the LORD by the hand of Moses.