(20) To the end that he may prolong his days in his kingdom, he, and his children.—Shows that the kingdom in Israel would be hereditary only so far as Jehovah willed it to be so. Again we may say that the striking fact that no dynasty except that of David ever continued for more than five generations, and only two dynasties for more than two generations, while David’s dynasty was perpetual by promise, could hardly have escaped notice, if known to the writer of this book.

Deuteronomy 17:20. That his heart be not lifted up — He intimates, that the Scriptures, diligently read, are a powerful means to keep a person humble, because they show him that, though a king, he is subject to a higher monarch, to whom he must give an account of all his administrations, and receive from him his sentence, agreeably to their quality, which is sufficient to abate the pride of the haughtiest person in the world.

17:14-20 God himself was in a particular manner Israel's King; and if they set another over them, it was necessary that he should choose the person. Accordingly, when the people desired a king, they applied to Samuel, a prophet of the Lord. In all cases, God's choice, if we can but know it, should direct, determine, and overrule ours. Laws are given for the prince that should be elected. He must carefully avoid every thing that would turn him from God and religion. Riches, honours, and pleasures, are three great hinderances of godliness, (the lusts of the flesh, the lusts of the eye, and the pride of life,) especially to those in high stations; against these the king is here warned. The king must carefully study the law of God, and make that his rule; and having a copy of the Scriptures of his own writing, must read therein all the days of his life. It is not enough to have Bibles, but we must use them, use them daily, as long as we live. Christ's scholars never learn above their Bibles, but will have constant occasion for them, till they come to that world where knowledge and love will be made perfect. The king's writing and reading were as nothing, if he did not practise what he wrote and read. And those who fear God and keep his commandments, will fare the better for it even in this world.It is in striking consistency with the dignity which everywhere throughout the Mosaic legislation surrounds the chosen people of God, that even if they will be "like as all the nations about" Deuteronomy 17:14, and be governed by a king, care should nevertheless be taken that he shall be no Oriental despot. He is to be of no royal caste, but "one from among thy brethren" Deuteronomy 17:15; he is to bear himself as a kind of "primus inter pares," his heart "not being lifted up above his brethren" Deuteronomy 17:20; he is, like his subjects, to be bound by the fundamental laws and institutions of the nation, and obliged, as they were, to do his duty in his station of life with constant reference thereto. The spirit of the text is that of Matthew 23:9.

A copy of this law - The whole Pentateuch, or, at any rate, the legal portion of the Pentateuch.

A book ... before the priests the Levites - Compare the marginal reference.

20. that he may prolong his days in his kingdom, he and his children—From this it appears that the crown in Israel was to be hereditary, unless forfeited by personal crime. That his heart be not lifted up; he intimates, that the Scriptures, diligently read and studied, are a powerful and probable means to keep him humble, because they show him that, though a king, he is subject to a 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.

That his heart be not lifted up above his brethren,.... On account of his office, the dignity of it, considering that he was subject to the law of God, and accountable to the Lord for all his actions:

and that he turn not aside from the commandment, to the right hand or to the left; not in the least deviate from the law of God in the whole of his conduct, and particularly in the exercise of his kingly office:

to the end that he may prolong his days in his kingdom; ruling well according to the laws of God being the way to rule long:

he and his children in the midst of Israel; this shows, as Jarchi observes, that if his son was fit for the kingdom, he was to be preferred to any other man; for though it was elective, yet to be continued in the same family, provided they walked in the ways of the Lord, and observed his laws.

That his heart be not lifted up above his {o} 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 days in his kingdom, he, and his children, in the midst of Israel.

(o) By which is meant that kings should love their subjects as nature causes one brother to love another.