Deuteronomy 7:2, 3, 16
Deuteronomy 7:2 NIV
and when the LORD your God has delivered them over to you and you have defeated them, then you must destroy them totally. Make no treaty with them, and show them no mercy.
Deuteronomy 7:3 NIV
Do not intermarry with them. Do not give your daughters to their sons or take their daughters for your sons
Deuteronomy 7:16 NIV
You must destroy all the peoples the LORD your God gives over to you. Do not look on them with pity and do not serve their gods, for that will be a snare to you.