Deuteronomy 10:8

10:8 At that time the Lord set apart the tribe of Levi to carry the ark of the Lord’s covenant, to stand before the Lord to serve him, and to formulate blessings in his name, as they do to this very day.

Deuteronomy 17:12

17:12 The person who pays no attention to the priest currently serving the Lord your God there, or to the verdict – that person must die, so that you may purge evil from Israel.

Deuteronomy 21:5

21:5 Then the Levitical priests will approach (for the Lord your God has chosen them to serve him and to pronounce blessings in his name, and to decide every judicial verdict)