Matthew 12:8 - Ellicott's Commentary On The Whole Bible

For the Son of man. — The words contain the ground for the authoritative judgment of the previous verse. They assert that this also came within the limits of His jurisdiction as the Messiah, just as the power to forgive sins had been claimed by Him under the same title. In both instances, however, the choice of the title is significant. What is done is done by Him as the representative of humanity, acting, as it were, in its name, and claiming for it as such what He thus seems at first to claim for Himself as a special and absolute prerogative.