In his Gospel St. Matthew portrays Jesus as a new and greater Moses. It was on a mountain Sinai, that Moses delivered the Law of God. Now it’s on a mountainside, in His Sermon on the Mount, that Jesus delivers the new law. When He says, “You have learnt how it was said to our ancestors…â€, His audience know at once that He is referring to Moses, and to the Law that Moses had received from God on Sinai.
According to the Law, murder is wrong: yes, says Jesus, but so too is anger, which so easily flares into violence; indeed, it is better not to come to worship if you harbor hatred for a sister or brother. According to the Law, adultery is wrong: yes, says Jesus, but so too is looking lustfully at another human being for that is, at least in intent, a violating of the other.
Jesus Himself tells us that in the end the whole of the Law and the Prophets hangs on the double commandment of loving God and loving our neighbor. Morover, it is in rising to this twofold love that we prove our love for Him. “If you love meâ€, He will tell His friends in John’s Gospel, “keep My commandments.â€