The scribes never spoke their objection out loud, and Jesus answered it anyway. His question shows them that He knows their hearts. Barnes notes that "the power of searching the heart, and of knowing the thoughts of people, belongs only to God." Gill is careful about what the evil was: "it was no evil in them to think that God only could forgive sin; but the evil was, that they thought Christ was a mere man, and ought not to have took so much upon him." Mark records their reasoning: "who can forgive sins but God only?" (Mark 2:7). The question invites them to examine the judgment they had already passed on Him.

The scribes give no recorded answer. Jesus asks a second question, "For whether is easier, to say, Thy sins be forgiven thee; or to say, Arise, and walk?" (Matthew 9:5). Then He proves His authority: "But that ye may know that the Son of man hath power on earth to forgive sins," He tells the man, "Arise, take up thy bed, and go unto thine house" (Matthew 9:6). The man "arose, and departed to his house," and the multitudes "marvelled, and glorified God" (Matthew 9:7-8).

"Thoughts" translates enthumēseis, which Thayer defines as "a thinking, consideration." The same word is used when "Jesus knew their thoughts" in Matthew 12:25. In the Greek texts printed on BibleHub, the Textus Receptus reads that Jesus was "seeing" (idōn) their thoughts, while other texts read "knowing" (eidōs); the KJV and ESV both say "knowing."

To blaspheme, Barnes explains, "originally means to speak evil of anyone." Applied to God, it means to speak of Him wrongly. The scribes thought Jesus was claiming a right that belonged only to God.

This question reveals who Jesus is. In the Old Testament, searching hearts is the work of God: "I the LORD search the heart" (Jeremiah 17:10), and "the LORD searcheth all hearts, and understandeth all the imaginations of the thoughts" (1 Chronicles 28:9). Barnes cites both passages here. Jesus reads the scribes' hearts and then forgives sins, two things Scripture says belong to God alone. Even the scribes asked, "who can forgive sins but God only?" (Mark 2:7). Gill calls His knowledge of their thoughts "a clear evidence, and full demonstration of his deity."

Jesus also answers His critics. He did not simply expose them. He gave them evidence they could see, healing the man "that ye may know" (Matthew 9:6). Matthew Henry writes, "Our Lord Jesus has perfect knowledge of all that we say within ourselves."