9 And thou shalt come unto the priests, the Levites, and unto the judge that shall be in those days, and inquire; and they shall declare unto thee the sentence of judgment;

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.