Deuteronomy 18:5-7

New Century Version

⁵ The Lord your God has chosen the priests and their descendants out of all your tribes to stand and serve the Lord always.

⁶ If a Levite moves from one of your towns anywhere in Israel where he lives and comes to the place the Lord will choose, because he wants to serve the Lord there, ⁷ he may serve the Lord his God. He will be like his fellow Levites who serve there before the Lord.