Deuteronomy 10:8
At that time the LORD separated the tribe of Levi, to bear the ark of the covenant of the LORD, to stand before the LORD to minister unto him, and to bless in his name, unto this day. At that time the LORD separated the tribe of Levi, to bear the ark of the covenant of the LORD, to stand before the LORD to minister unto him, and to bless in his name, unto this day.
At that time the Lord separated the tribe of Levi to bear the ark of the covenant, to stand before Him to minister to Him, and to bless in His name. That separation made the Levites ministers of the sanctuary. Their sanctuary ministry included teaching the people.
By faithfulness and repentance the curse resting on Levi for his ancestor's cruelty was transformed into an honor, and in that faithfulness his descendants received this appointed office. They were given no landed inheritance but lived in designated cities and were supported by tithes, gifts, and offerings. The Lord Himself was their inheritance.