11 According to the sentence of the law in which they instruct you, according to the judgment which they tell you, you shall do; you shall not turn aside to the right hand or to the left from the sentence which they pronounce upon you.

Matthew Henry's Commentary on Deuteronomy 17:11

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.