Albert Barnes Commentary Matthew 9:3

"And behold, certain of the scribes said within themselves, This man blasphemeth." — Matthew 9:3 (ASV)

This man blasphemeth. The word blaspheme originally means to speak evil of anyone, to injure by words, or to blame unjustly. When applied to God, it means to speak of him unjustly, to ascribe to him acts and attributes which he does not possess, or to speak impiously or profanely.

It also means to say or do anything by which his name or honour is insulted, or which conveys an unfavorable impression of God. It also means to attempt to do or say a thing that belongs to him alone, or that only he can do. This is its meaning here.

Christ was charged with saying a thing in his own name, or attempting to do a thing that properly belonged to God; thus assuming the place of God and, as the scribes supposed, doing him injury by an invasion of his prerogatives. "None," they said (Luke 5:21), "can forgive sins but God only." In this they reasoned correctly.

See Isaiah 43:25; 44:22. None of the prophets had this power. By saying that he forgave sins, Jesus was understood to affirm that he was Divine. And since he proved this by working a miracle expressly to confirm the claim, it follows that he is Divine, or equal with the Father.