Deuteronomy 18:4-6

New Revised Standard Version Catholic Edition

⁴ The first fruits of your grain, your wine, and your oil, as well as the first of the fleece of your sheep, you shall give him. 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),