9 And you shall come to the Levitical priests and to the judge who is in office in those days, and you shall consult them, and they shall declare to you the decision. 10 Then you shall do according to what they declare to you from that place that the Lord will choose. And you shall be careful to do according to all that they direct you. 11 According to the instructions that they give you, and according to the decision which they pronounce to you, you shall do. You shall not turn aside from the verdict that they declare to you, either to the right hand or to the left. 12 The man who acts presumptuously by not obeying the priest who stands to minister there before the Lord your God, or the judge, that man shall die. So you shall 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.