Matthew Poole and continuators on Deuteronomy 17:20

20 That his heart be not lifted up above his brethren , and that he turn not aside from the commandment, to the right hand, or to the left: to the end that he may prolong his dayes in his kingdom, he, and his children in the midst of Israel.

He intimates, that the Scriptures diligently read and studied, are a powerful and probable means to keep him humble, because they shew him that, though a king, he is subject to an higher Monarch, to whom he must give an account of all his administrations and actions, and receive from him his sentence and doom agreeable to their quality, which is sufficient to abate the pride of the haughtiest person in the world, if he duly consider it.