Numbers 3:27-28, 32, 38

To Kohath belonged the clan of the Amramites and the clan of the Izharites and the clan of the Hebronites and the clan of the Uzzielites; these are the clans of the Kohathites. According to the number of all the males, from a month old and upward, there were 8,600, keeping guard over the sanctuary.

And Eleazar the son of Aaron the priest was to be chief over the chiefs of the Levites, and to have oversight of those who kept guard over the sanctuary.

Those who were to camp before the tabernacle on the east, before the tent of meeting toward the sunrise, were Moses and Aaron and his sons, guarding the sanctuary itself, to protect the people of Israel. And any outsider who came near was to be put to death.