Deuteronomy 7:9-11

7:9 So realize that the Lord your God is the true God, the faithful God who keeps covenant faithfully with those who love him and keep his commandments, to a thousand generations, 7:10 but who pays back those who hate him as they deserve and destroys them. He will not ignore those who hate him but will repay them as they deserve! 7:11 So keep the commandments, statutes, and ordinances that I today am commanding you to do.