Deuteronomy 7:3-5

You shall not intermarry with them, giving your daughters to their sons or taking their daughters for your sons, for they would turn away your sons from following me, to serve other gods. Then the anger of the LORD would be kindled against you, and he would destroy you quickly. But thus shall you deal with them: you shall break down their altars and dash in pieces their pillars and chop down their Asherim and burn their carved images with fire.