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.
Numbers 10:5
5 When you blow an alarm, mthe camps that are on the east side shall set out.