Deuteronomy 7:1-7

1 When the Lord your God takes you into the land where you are going, which is to be your heritage, and has sent out the nations before you, the Hittites and the Girgashites and the Amorites and the Canaanites and the Perizzites and the Hivites and the Jebusites, seven nations greater and stronger than you;
2 And when the Lord has given them up into your hands and you have overcome them, give them up to complete destruction: make no agreement with them, and have no mercy on them:
3 Do not take wives or husbands from among them; do not give your daughters to their sons, or take their daughters for your sons.
4 For through them your sons will be turned from me to the worship of other gods: and the Lord will be moved to wrath against you and send destruction on you quickly.
5 But this is what you are to do to them: their altars are to be pulled down and their pillars broken, and their holy trees cut down and their images burned with fire.
6 For you are a holy people to the Lord your God: marked out by the Lord your God to be his special people out of all the nations on the face of the earth.
7 The Lord did not give you his love or take you for himself because you were more in number than any other people; for you were the smallest of the nations: