Deuteronomy 18:1

18:1 The priests the Levites, [and] all the tribe of Levi, shall have no part nor inheritance with Israel: they shall eat the offerings of the LORD made by fire, and his inheritance.

Deuteronomy 18:5

18:5 For the LORD thy God hath chosen him out of all thy tribes, to stand to minister in the name of the LORD, him and his sons for ever.