Deuteronomy 17:20

20 He won't think of himself as being better than his people are. He won't turn away from the law. He won't turn to the right or the left. Then he and his sons after him will rule over his kingdom in Israel for a long time.

Deuteronomy 17:20 Meaning and Commentary

Deuteronomy 17:20

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.

Deuteronomy 17:20 In-Context

18 When he sits on the throne of his kingdom, he must make himself a copy of the law I'm teaching you. He must write it on a scroll. He must copy it from the scroll of a priest, who is a Levite.

19 The king must keep the scroll close to him at all times. He must read it all the days of his life. Then he can learn to have respect for the LORD his God. He can carefully follow all of the words of that law and those rules.

20 He won't think of himself as being better than his people are. He won't turn away from the law. He won't turn to the right or the left. Then he and his sons after him will rule over his kingdom in Israel for a long time.