Moses was a type of Christ. Both He and brother Aaron were Levites, which represented the priesthood. In the Book of Exodus we have Moses as the Judge, because He knew - the Word of the LORD. Moses would sit in His seat and hear cases all day, until corrected by Jethro, His father in law.
The people would stand all day to settle cases between each other, and would be worn down by the process; so would the Judge. Jethro was a priest himself, and gave Moses great wisdom[Ex.18:17-22]. Moses was to teach GOD's rules to a specific group of leaders, that would become judges over the people.
These judges? "Able men, that fear GOD, men of truth, hating covetousness." Christ Jesus was born a Levite, because of His Mother. He exposed the leaders of His time in the flesh, as FAKES. They practiced what He called "The Traditions of Men"[from Satan] which voided out the Word of GOD.
The Books of Ezra & Nehemiah shows us how the Priesthood became polluted. Look around today at whom is wearing robes, and what are they judging based on?? Many are deceived into thinking that it is Moses Law[given by YHVH], or the Constitutions that were founded on Mosaic Law.
The Book of Deuteronomy is a re-cap of the first Four Books of Moses. Deut.1:6 a reminder on picking leaders. Deut.1:16 is a "charge" to judges. Any spirit, or body that brings anything additional, is bringing Pollution into God's business.