Deuteronomy 7:3-5

Neither shalt thou make marriages with them. Thou shalt not give thy daughter to his son, nor take his daughter for thy son:

For she will turn away thy son from following me, that he may rather serve strange gods, and the wrath of the Lord will be kindled, and will quickly destroy thee.

But thus rather shall you deal with them: Destroy their altars, and break their statues, and cut down their groves, and burn their graven things.