9 where you shall consult with the levitical priests and the judge who is in office in those days; they shall announce to you the decision in the case.

Matthew Henry's Commentary on Deuteronomy 17:9

Commentary on Deuteronomy 17:8-13

(Read Deuteronomy 17:8-13)

Courts of judgment were to be set up in every city. Though their judgment had not the Divine authority of an oracle, it was the judgment of wise, prudent, experienced men, and had the advantage of a Divine promise.