Numbers 1:53
53 But nthe Levites shall camp around the tabernacle of the testimony, oso that there may be no wrath on the congregation of the people of Israel. And pthe Levites shall keep guard over the tabernacle of the testimony.”
Numbers 3:38
38 Those who were to camp before the tabernacle qon the east, before the tent of meeting toward the sunrise, were Moses and Aaron and his sons, rguarding the sanctuary itself, to protect1 the people of Israel. And sany outsider who came near was to be put to death.