Adam Clarke on Proverbs 20:8

A king that sitteth in the throne of judgment - Kings should see to the administration of the laws, as well as of the state transactions, of their kingdom. In the British constitution there is a court for the king, called the King's Bench, where he should sit, and where he is always supposed to be sitting. The eyes - the presence, of the monarch in such a place, scatter evil - he sees into the case himself, and gives right judgment, for he can have no self-interest. Corrupt judges, and falsifying counsellors, cannot stand before him; and the villain is too deeply struck with the majesty and state of the monarch, to face out iniquity before him.