Deuteronomy 17:17-19 New International Version - UK (NIVUK)
17 He must not take many wives, or his heart will be led astray. He must not accumulate large amounts of silver and gold.
18 When he takes the throne of his kingdom, he is to write for himself on a scroll a copy of this law, taken from that of the Levitical priests. 19 It is to be with him, and he is to read it all the days of his life so that he may learn to revere the Lord his God and follow carefully all the words of this law and these decrees