When the camp is supposed to move, Aaron and his sons will go in and take down the canopy that hangs over the ark containing the words of God’s promise. First they will cover the ark with the canopy.
The Lord said, “Tell your brother Aaron that he cannot go into the holy place whenever he wants to. If he goes up to the canopy and stands in front of the throne of mercy on the ark, he will die, because I appear in the smoke above the throne of mercy.
“When Aaron and his sons have finished covering the holy things and the camp is ready to move, the Kohathites will come to carry all the holy articles. They must never touch the holy things, or they will die. The Kohathites will carry all the things from the tent of meeting.
But Moses gave none of these gifts to the Kohathites, because they took care of the holy things. They had to carry the holy things on their own shoulders.
God struck down some of the people from Beth Shemesh because they looked inside the ark of the Lord. He struck down 70 people. The people mourned because the Lord struck them with such a great blow.