Deuteronomy 17:14-20 New King James Version (NKJV)
Principles Governing Kings
14 “When you come to the land which the Lord your God is giving you, and possess it and dwell in it, and say, ‘I will set a king over me like all the nations that are around me,’ 15 you shall surely set a king over you whom the Lord your God chooses; one from among your brethren you shall set as king over you; you may not set a foreigner over you, who is not your brother. 16 But he shall not multiply horses for himself, nor cause the people to return to Egypt to multiply horses, for the Lord has said to you, ‘You shall not return that way again.’ 17 Neither shall he multiply wives for himself, lest his heart turn away; nor shall he greatly multiply silver and gold for himself.
18 “Also it shall be, when he sits on the throne of his kingdom, that he shall write for himself a copy of this law in a book, from the one before the priests, the Levites. 19 And it shall be with him, and he shall read it all the days of his life, that he may learn to fear the Lord his God and be careful to observe all the words of this law and these statutes, 20 that his heart may not [a]be lifted above his brethren, that he may not turn aside from the commandment to the right hand or to the left, and that he may [b]prolong his days in his kingdom, he and his children in the midst of Israel.
Deuteronomy 17:14-20 New International Version (NIV)
14 When you enter the land the Lord your God is giving you and have taken possession of it and settled in it, and you say, “Let us set a king over us like all the nations around us,” 15 be sure to appoint over you a king the Lord your God chooses. He must be from among your fellow Israelites. Do not place a foreigner over you, one who is not an Israelite. 16 The king, moreover, must not acquire great numbers of horses for himself or make the people return to Egypt to get more of them, for the Lord has told you, “You are not to go back that way again.” 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 20 and not consider himself better than his fellow Israelites and turn from the law to the right or to the left. Then he and his descendants will reign a long time over his kingdom in Israel.