Deuteronomy 7:3-5

neither shalt thou make marriages with them; thy daughter thou shalt not give unto his son, nor his daughter shalt thou take unto thy son.

For he will turn away thy son from following me, that they may serve other gods: so will the anger of Jehovah be kindled against you, and he will destroy thee quickly.

But thus shall ye deal with them: ye shall break down their altars, and dash in pieces their pillars, and hew down their Asherim, and burn their graven images with fire.