Deuteronomy 17:18-20

When he is seated on his royal throne, he is to write a copy of this instruction for himself on a scroll in the presence of the Levitical priests. It is to remain with him, and he is to read from it all the days of his life, so that he may learn to fear the LORD his God, to observe all the words of this instruction, and to do these statutes. Then his heart will not be exalted above his countrymen, he will not turn from this command to the right or the left, and he and his sons will continue reigning many years in Israel.