But six times in the Sermon on the Mount, he introduced what sounded like statements from the Hebrew Scriptures with the words: “It was said.” (Matthew 5:21, 27, 31, 33, 38, 43) Why? Because he was referring to the Scriptures as interpreted in the light of Pharisaic traditions that contradicted God’s commandments. (Deuteronomy 4:2; Matthew 15:3)

14. How does Jesus counsel us not even to start down the road that leads to adultery?

¹⁴ Jesus next said: “You heard that it was said, ‘You must not commit adultery.’ But I say to you that everyone that keeps on looking at a woman so as to have a passion for her has already committed adultery with her in his heart.” (Matthew 5:27, 28) You are not going to commit adultery? Then do not even start down that road by entertaining thoughts about it. Guard your heart, where such things have their source. (Proverbs 4:23; Matthew 15:18, 19) James 1:14, 15 warns: “Each one is tried by being drawn out and enticed by his own desire. Then the desire, when it has become fertile, gives birth to sin; in turn, sin, when it has been accomplished, brings forth death.” People sometimes say: ‘Don’t start what you can’t finish.’ But in this case we should say: ‘Don’t start what you can’t stop.’ Some who have been faithful even when threatened with death before a firing squad have later fallen for the insidious lure of sexual immorality.