Sforno on Deuteronomy 16:18/ספורנו על דברים ט״ז:י״ח

1שופטים ושוטרים, after Moses had addressed a number of commandments to the people at large, he now turned to instruct the leaders of the people in commandments of special concern for them. By paying especial attention to observing these laws, the leaders, especially the judges, kings and prophets, would be able to maintain the spiritual level of the people at large, and thus ensure the people’s continued tenure of the Land of Israel. In the words of the prophet: “when the lion roars who does not tremble?” (Amos 3,8) Tzefaniah phrased it somewhat differently, providing degrees of reactions to people in varying degrees of authority. (Tzefaniah 3,3 describes the princes, leading authorities as being feared like roaring lions, whereas the judges who have no executive powers are feared in the manner one is afraid of wolves.)

2נותן לך לשבטיך, in the gates (cities) He is about to give to you. You are to divide the judges to districts, i.e. each of your cities must have a judiciary. This restriction does not apply to land conquered outside the traditional boundaries of Israel; there, seeing the land was not divided into tribal parcels, the judiciary appointed also did not have to adhere to this pattern. Examples of such regions were Syria, etc.

3משפט צדק, the manner in which the complaints of the litigants were heard should be such that the resulting decisions could be expected to be fair, צדק, righteous. The judges were not to discriminate in their treatment of either of the opposing litigants.