Deuteronomy 17:9

Deuteronomy 17 forbids sacrificing to the Lord any blemished animal and prescribes the death penalty for anyone who worships other gods, established on the testimony of two or three witnesses whose hands strike first. For hard cases too difficult for local judges, it directs the people to go to the priests and judge at the place the Lord chooses and to obey their ruling absolutely. The chapter then anticipates a future king, requiring him to be the Lord's chosen, to avoid many horses, wives, and riches, and to write for himself a copy of the law and read it all his days so his heart is not lifted above his brethren.