Numbers 18:3-5

3They must take care of the Tent of Meeting on your behalf. You must tell them what they should do. They must not go near anything that is inside God's Holy Place or the altar. If they do, they will die, and you will die too.

4The Levites must work with you as they take care of the Tent of Meeting. No other people have authority to come near you as you work there.

5You must take care of God's Holy Place and the altar. Then I will not be angry with the Israelites again.