Charles Ellicott Commentary Matthew 12:8

"For the Son of man is lord of the sabbath." — Matthew 12:8 (ASV)

For the Son of man — These words provide the ground for the authoritative judgment in the previous verse. They assert that this also fell within the limits of His jurisdiction as the Messiah, just as He had claimed the power to forgive sins under the same title.

In both instances, however, the choice of the title is significant. What He does, He does as the representative of humanity, acting, so to speak, in its name. He is claiming for humanity what He at first seems to claim for Himself as a special and absolute prerogative.