In these laws concerning the king there are three prohibitions and one commandment. God wanted the king to write a copy of the law to know and obey God’s will. He had to write it down himself to imprint it well in his head and heart. If the king delights in God’s law and studies that law day and night, his reign will be very fruitful and his kingdom will prosper (compare Psalm 1:1–3).
18 “And when he sits on the throne of his kingdom, he shall write for himself in a book a copy of this law, approved by the Levitical priests.