Numbers 1:52-54

52The children of Israel shall pitch their tents, everyone by his own camp, everyone by his own standard, according to their armies;

53but the Levites shall camp around the tabernacle of the Testimony, that there may be no wrath on the congregation of the children of Israel; and the Levites shall keep charge of the tabernacle of the Testimony.”

54Thus the children of Israel did; according to all that the Lord commanded Moses, so they did.