Numbers 3:29

The families of the sons of Kohath shall pitch on the side of
the tabernacle southward.
] Or to the right, which was the more honourable place, excepting the east or front, which was reserved for Moses and Aaron, and his sons, and who were one of these families; and is the reason why this honour was conferred upon them, as well as they had the more honourable charge, having the holy places and holy things committed to their care; and one from among them was appointed over all the Levites, and the chief of them, as they had also, when they came into the land of Canaan, almost as many cities of refuge as both their other brethren had: their situation about the tabernacle was between that and the camp of Reuben, and this accounts for it, how Korah who was of one of the families of the Kohathites, became so intimately acquainted with, and joined in a conspiracy with Dathan and Abiram, who were of the tribe of Reuben, ( Numbers 16:1 ) .