What is an example of Jesus unpacking the true and full meaning of the law?

Jesus, for instance, raises the issue of the Old Testament’s eye-for-an-eye rule (Exodus 21:24–25). This principle was designed to limit penalties assessed in civil and criminal court cases. It was never supposed to authorize private retaliation for petty insults and personal infractions. It was a principle that kept the legal system in check, not a rule designed to unleash neighbor against neighbor in a back-and-forth war of attacks and counter-attacks. But the Pharisees had basically turned it into that. Personal vengeance poisoned the social atmosphere of Israel, and the religious leaders justified it by an appeal to Moses. Jesus said that was a total misuse and abuse of Moses’ law.