Deuteronomy 10:8-10

New International Version - UK

⁸ At that time the Lord set apart the tribe of Levi to carry the ark of the covenant of the Lord, to stand before the Lord to minister and to pronounce blessings in his name, as they still do today. ⁹ That is why the Levites have no share or inheritance among their fellow Israelites; the Lord is their inheritance, as the Lord your God told them.)

¹⁰ Now I had stayed on the mountain for forty days and forty nights, as I did the first time, and the Lord listened to me at this time also. It was not his will to destroy you.