Deuteronomy 7:2-4

New Catholic Bible

² and when the Lord, your God, will have delivered them over to you and you will have defeated them, you are to wipe them out. You are not to make a covenant with them or show them any mercy. ^3 [a]Do not intermarry with them. Do not give your daughters to their sons nor take their daughters for your sons. ⁴ They would turn your sons away from serving me to serve other gods and the anger of the Lord would be kindled against you and destroy you in an instant.