In Matthew 5, as part of His Sermon on the Mount, Jesus repeats the phrase “but I say to you” several times. This is extremely significant, as Jesus is establishing His authority and setting His teaching above the teaching of the scribes and Pharisees. Let’s take a closer look at each occurrence of this phrase in Matthew 5:
Matthew 5:21-22 – Murder
“You have heard that it was said to those of old, ‘You shall not murder; and whoever murders will be liable to judgment.’ But I say to you that everyone who is angry with his brother will be liable to judgment; whoever insults his brother will be liable to the council; and whoever says, ‘You fool!’ will be liable to the hell of fire.”
Jesus quotes one of the Ten Commandments, “You shall not murder,” but then immediately states “but I say to you” and expands the commandment to include anger, insults and saying “You fool!” Jesus is establishing His authority over the Old Testament law, showing that He has come to fulfill the law and the prophets (Matthew 5:17). Not only is murder wrong, but the heart attitudes that lead to murder are equally wrong in God’s eyes.
Matthew 5:27-28 – Adultery
“You have heard that it was said, ‘You shall not commit adultery.’ But I say to you that everyone who looks at a woman with lustful intent has already committed adultery with her in his heart.”
Again Jesus quotes one of the Ten Commandments, “You shall not commit adultery,” and then asserts “but I say to you” and expands the commandment to include lustful intent and thought. Jesus gets to the heart of the matter, literally. It’s not just actions but our thought life that God examines. Adultery begins internally before being manifested externally.
Matthew 5:31-32 – Divorce
“It was also said, ‘Whoever divorces his wife, let him give her a certificate of divorce.’ But I say to you that everyone who divorces his wife, except on the ground of sexual immorality, makes her commit adultery, and whoever marries a divorced woman commits adultery.”
Jesus references the certificate of divorce allowance within the law of Moses and supersedes it with His own authoritative statement: “But I say to you” that divorce leads to adultery, unless on grounds of sexual immorality. Again, Jesus’ teaching transcends the Old Testament law. He calls for a higher standard regarding marriage and faithfulness.
Matthew 5:33-34 – Oaths
“Again you have heard that it was said to those of old, ‘You shall not swear falsely, but shall perform to the Lord what you have sworn.’ But I say to you, Do not take an oath at all, either by heaven, for it is the throne of God, or by the earth, for it is his footstool…”
The Old Testament allowed for oath-taking so long as you fulfilled your vows. But Jesus says oaths should not even be taken in the first place. Do not swear by God’s name or heaven or earth. But simply let your yes be yes, and your no be no (Matthew 5:37). Jesus calls for complete honesty and integrity apart from oaths.
Matthew 5:38-39 – Eye for Eye
“You have heard that it was said, ‘An eye for an eye and a tooth for a tooth.’ But I say to you, Do not resist the one who is evil. But if anyone slaps you on the right cheek, turn to him the other also.”
The Old Testament prescribed fair punishment and retribution for crimes committed: an eye for an eye. But Jesus supersedes this and calls for non-retaliation, even to the point of turning the other cheek. He calls for grace and kindness even towards enemies. This would have been radical and countercultural in Jesus’ day, just as it is in ours.
Matthew 5:43-44 – Love Your Enemies
“You have heard that it was said, ‘You shall love your neighbor and hate your enemy.’ But I say to you, Love your enemies and pray for those who persecute you…”
The Old Testament never actually says to hate your enemy, but it was likely a cultural understanding of texts like Psalm 139:21-22. Regardless, Jesus states that we are to go beyond just loving our neighbors and are to even love and pray for our enemies. This kind of radical, unconditional love would have shocked Jesus’ original audience.
The Significance
In all of these instances where Jesus says “but I say to you,” He is establishing His divine authority over the Old Testament law and the teachings of the religious leaders of the day. As the very Son of God, Jesus has the right to alter, expand and clarify God’s commands. He calls His followers to a higher standard of heart obedience. It’s not just about right actions but right attitudes. Jesus cared far more about people’s hearts than just surface-level obedience or rule-following. Time and again He condemned the Pharisees for appearing righteous on the outside but being unrighteous within their hearts (Matthew 23:25-28).
Additionally, Jesus’ commands to non-retaliation, loving enemies, not divorcing, and not swearing oaths would have seemed impossible to fully obey. And they are! By calling for such a high standard, Jesus shows that we are unable to be righteous enough to earn salvation on our own. We need grace. We need Jesus’ perfect righteousness credited to us (2 Corinthians 5:21). The Sermon on the Mount shows our desperate need for a Savior to redeem us and also gives the Holy Spirit’s guidance for how to live. Jesus gives extremely challenging commands here – but remember, He doesn’t just tell us what to do, He enables what He requires (Philippians 2:13). By God’s grace, the righteous requirements of the law can be fulfilled in us as we walk by the Spirit (Romans 8:4).