After the Beatitudes at the beginning of Matthew 5, the rest of the chapter is filled with short snippets of texts that are very familiar to our ears. The first one that Jesus addresses is the topic of anger.
“You have heard it said…” That’s how Jesus introduces many of these topics. And for most of his hearers, they had heard it said. They would have been very familiar with the Mosaic Law, and for those who were part of the Council, the Sanhedrin, they would have been intimately familiar with it. They knew it frontwards and backwards. But they were missing the point.
Moses had given them this Law, and had done so while the nation of Israel was encamped around Mount Sinai, after the exodus from Egypt. But even though it came through Moses, he wasn’t the author… God was.
Jesus is about to turn their understanding of both the Law and its Author completely upside down.
He takes a phrase that they would have known well, “You shall not commit murder” (Exodus 20:13; Matthew 5:21), and completely reinterprets it. Murder was wrong, God had told them so when the Law was given.
But Jesus then states, “But I say to you…” He gives a new understanding of the Law. And he does it with the forceful authority of the Lawgiver, God himself. His hearers, especially those in the religious council, would have heard both messages quite clearly: Jesus was giving them a new understanding of the passage, and he was claiming to be God in the process.