Jesus opens this section of the Sermon on the Mount with a phrase that should arrest us immediately: “You have heard that it was said.” He is not quoting a rabbinical error. He is quoting the law of God rightly, specifically the sixth commandment from Exodus 20:13. The command is clear: do not murder. And the Pharisees were content to stop there. No bodies, no violation.
But Jesus does not let his hearers off that easily. By saying, “But I say to you,” he is not contradicting Moses. He is doing something more surprising: he is showing that Moses was pointing to something much deeper than the Pharisees had ever allowed the text to reach. The sixth commandment was always about more than the literal act of unlawful killing.
The Greek word here is the word for murder, not for killing in general. The prohibition excludes self-defense, warfare with due legal sanction, accidental death, and capital punishment following lawful process. The commandment was never a blanket prohibition on all taking of life. It was always targeted at the unjust, murderous devaluing of another human being.
Jesus is not lowering the bar. He is showing us that the bar was always higher than we imagined. The sixth commandment is the floor of Christian ethics, not the ceiling. We begin there. We do not end there. And most of us, it turns out, have never properly understood even the floor.