Deuteronomy 7:10 (KJV)

But because the Lord loved you, and because he would keep the oath which he had sworn unto your fathers, hath the Lord brought you out with a mighty hand, and redeemed you out of the house of bondmen, from the hand of Pharaoh king of Egypt.

Know therefore that the Lord thy God, he is God, the faithful God, which keepeth covenant and mercy with them that love him and keep his commandments to a thousand generations;

And repayeth them that hate him to their face, to destroy them: he will not be slack to him that hateth him, he will repay him to his face.

Thou shalt therefore keep the commandments, and the statutes, and the judgments, which I command thee this day, to do them.

Wherefore it shall come to pass, if ye hearken to these judgments, and keep, and do them, that the Lord thy God shall keep unto thee the covenant and the mercy which he sware unto thy fathers: