Charles Ellicott Commentary Deuteronomy 7:9-11

"Know therefore that Jehovah thy God, he is God, the faithful God, who keepeth covenant and lovingkindness 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 commandment, and the statutes, and the ordinances, which I command thee this day, to do them." — Deuteronomy 7:9-11 (ASV)

These verses are a direct comment on the second commandment. Thousands of them that love Him are here expanded into a thousand generations. The “hatred,” too, is the same thing denoted there: You shall therefore keep the commandments.