Deuteronomy 7:11 (KJV)

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:

And he will love thee, and bless thee, and multiply thee: he will also bless the fruit of thy womb, and the fruit of thy land, thy corn, and thy wine, and thine oil, the increase of thy kine, and the flocks of thy sheep, in the land which he sware unto thy fathers to give thee.