Deuteronomy 17:19
15 you must select without fail a king whom the Lord your God chooses. From among your fellow citizens you must appoint a king—you may not designate a foreigner who is not one of your fellow Israelites. 16 Moreover, he must not accumulate horses for himself or allow the people to return to Egypt to do so, for the Lord has said you must never again return that way. 17 Furthermore, he must not marry many wives lest his affections turn aside, and he must not accumulate much silver and gold. 18 When he sits on his royal throne he must make a copy of this law on a scroll given to him by the Levitical priests. 19 It must be with him constantly, and he must read it as long as he lives, so that he may learn to revere the Lord his God and observe all the words of this law and these statutes and carry them out. 20 Then he will not exalt himself above his fellow citizens or turn from the commandments to the right or left, and he and his descendants will enjoy many years ruling over his kingdom in Israel.
2 Kings 23:2
1 The king summoned all the leaders of Judah and Jerusalem. 2 The king went up to the Lord’s temple, accompanied by all the people of Judah, all the residents of Jerusalem, the priests, and the prophets. All the people were there, from the youngest to the oldest. He read in their ears2 all the words of the scroll of the covenant that had been discovered in the Lord’s temple. 3 The king stood by the pillar and renewed the covenant before the Lord, agreeing to follow the Lord and to obey his commandments, laws, and rules with all his heart and being, by carrying out the terms of this covenant recorded on this scroll. All the people agreed to keep the covenant.
Notes and References
"... Josiah is presented as an ideal monarch after the model of Moses as indicated by 2 Kings 23:25. Whereas Hezekiah follows the commands given by YHWH to Moses, Josiah reads the Torah of Moses in accordance with the description of the Deuteronomistic History's ideal monarch in Deuteronomy 17:14–20 ..."
Sweeney, Marvin A. King Josiah of Judah: The Lost Messiah of Israel (pp. 62-63) Oxford University Press, 2001