Deuteronomy 17:19-20

and it shall be with him, and he shall read therein all the days of his life; that he may learn to fear Jehovah his God, to keep all the words of this law and these statutes, to do them; 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 days in his kingdom, he and his children, in the midst of Israel.