Deuteronomy 7:2-4

and when the LORD your God delivers them over to you, you shall conquer them and utterly destroy them. You shall make no covenant with them nor show mercy to them. Nor shall you make marriages with them. You shall not give your daughter to their son, nor take their daughter for your son. For they will turn your sons away from following Me, to serve other gods; so the anger of the LORD will be aroused against you and destroy you suddenly.