Deuteronomy 7:2-6

and when the LORD your God gives them over to you, and you defeat them, then you must devote them to complete destruction. You shall make no covenant with them and show no mercy to them. You shall not intermarry with them, giving your daughters to their sons or taking their daughters for your sons, for they would turn away your sons from following me, to serve other gods. Then the anger of the LORD would be kindled against you, and he would destroy you quickly. But thus shall you deal with them: you shall break down their altars and dash in pieces their pillars and chop down their Asherim and burn their carved images with fire. “For you are a people holy to the LORD your God. The LORD your God has chosen you to be a people for his treasured possession, out of all the peoples who are on the face of the earth.