Deuteronomy 8:18-20

18But thou shalt remember the LORD thy God: for it is he that giveth thee power to get wealth, that he may establish his covenant which he swore to thy fathers, as it is this day. 19And it shall be, if thou shalt at all forget the LORD thy God, and walk after other gods, and serve them, and worship them, I testify against you this day that ye shall surely perish. 20As the nations which the LORD destroyeth before your face, so shall ye perish; because ye would not be obedient to the voice of the LORD your God.