Numbers 18:20-24 - Duties Of The Levites
20 Then the LORD instructed Aaron, "You are not to have any inheritance in the land, nor are you to have any portion among the people. I am your portion and your inheritance among the Israelis.
21 As to the descendants of Levi, certainly I've given all the tithes in Israel as their inheritance in return for their services that they perform at the Tent of Meeting. 22 Therefore, the Israelis need no longer come to the Tent of Meeting, so they won't suffer the consequences of their sin and die. 23 The descendants of Levi are to perform the service of the Tent of Meeting and they are to bear their iniquity. This is to be a statute forever, throughout your generations, that they are not to receive an inheritance among the Israelis, 24 because I've given to the descendants of Levi the tithes that the Israelis bring to the LORD as raised offering. Therefore I told them that, unlike the Israelis, they won't receive an inheritance."
47 The descendants of Levi were not counted according to their ancestral houses 48 because the LORD had ordered Moses: 49 "Be sure not to number or count the tribe of Levi with the rest of the Israelis. 50 Instead, appoint the descendants of Levi over the Tent of Meeting, all the vessels, and everything in it. They are to carry the tent and all the vessels in it. They are to attend to it and camp around it. 51 Whenever the tent is ready for travel, the descendants of Levi are to take it down. When it's time to encamp, the descendants of Levi are to set it up. Any unauthorized person who approaches it is to be executed.
52 Then the Israelis are to encamp around the tent, arranged according to their company and the standard of their army. 53 But the descendants of Levi are to encamp on all sides of the Tent of Meeting so that divine wrath won't fall on the congregation of Israel. The descendants of Levi are to take care of the Tent of Meeting." 54 The Israelis observed everything that the LORD had commanded Moses, doing exactly what they were told.