Aaron and his sons, Eleazar and Ithamar, had to fully cover the sanctuary and all holy items before the camp could move. Non-Levitical tribes marched in front and behind the Levites, who carried the Tent of Meeting. The colors of the coverings showed the royalty of the objects.
They were so holy that even the Kohathites, whom God chose to handle them, could not touch the holy items, or they would die. This respect showed the holiness of Israel's Lord. Ignoring these rules was dangerous, as shown in 1 Samuel 6:19–20 and 2 Samuel 6:6–7.