The priests were primarily the ones privileged to explain God’s law,

The priests were teachers of the Law to the people, reading and explaining it to those coming to the sanctuary to worship. Also, when not on assigned duty, they would have wide opportunity for such teaching, whether in the area of the sanctuary or in other parts of the land. (De 33:10; 2Ch 15:3; 17:7-9; Mal 2:7)