Deuteronomy 18:5-7

New Revised Standard Version Catholic Edition

⁵ For the Lord your God has chosen Levi^[a] out of all your tribes, to stand and minister in the name of the Lord, him and his sons for all time.

⁶ If a Levite leaves any of your towns, from wherever he has been residing in Israel, and comes to the place that the Lord will choose (and he may come whenever he wishes), ⁷ then he may minister in the name of the Lord his God, like all his fellow-Levites who stand to minister there before the Lord.