Deuteronomy 17:14-15

When thou art come unto the land which Jehovah thy God giveth thee, and shalt possess it, and shalt dwell therein, and shalt say, I will set a king over me, like all the nations that are round about me; thou shalt surely set him king over thee, whom Jehovah thy God shall choose: one from among thy brethren shalt thou set king over thee; thou mayest not put a foreigner over thee, who is not thy brother.