Deuteronomy 7:2-4

New King James Version

² and when the Lord your God delivers ^(A)them over to you, you shall conquer them and utterly destroy them. ^(B)You shall make no covenant with them nor show mercy to them. ^3 (C)Nor shall you make marriages with them. You shall not give your daughter to their son, nor take their daughter for your son. ⁴ For they will turn your sons away from following Me, to serve other gods; ^(D)so the anger of the Lord will be aroused against you and destroy you suddenly.