You have heard that it was said to the people of old, 'You will not murder,' and whoever murders will be liable to judgment.
In this passage Jesus recalls the Old Testament commandment, “Do not murder.” It was given in the Law of Moses (Exodus 20:13, Deut. 5:17). This commandment concerns murder and its consequences. The Law taught that murder is a grave sin, and the person who commits murder is subject to judgment.