9 and present them to the Levitical priests or the judge on duty at that time. They will hear the case and declare the verdict. 10 You must carry out the verdict they announce and the sentence they prescribe at the place the Lord chooses. You must do exactly what they say. 11 After they have interpreted the law and declared their verdict, the sentence they impose must be fully executed; do not modify it in any way. 12 Anyone arrogant enough to reject the verdict of the judge or of the priest who represents the Lord your God must die. In this way you will purge the evil from Israel.
Matthew Henry's Commentary on Deuteronomy 17:9-12
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.