Deuteronomy 17:14-15

14"When you come to the land that the Lord your God is giving you, and you possess it and dwell in it and then say, 'I will set a king over me, like all the nations that are around me,'

15you may indeed set a king over you whom the Lord your God will choose. One from among your brothers you shall set as king over you. You may not put a foreigner over you, who is not your brother.