Son of man -- authority to forgive sins

Matthew 9:1-8  And getting into a boat he crossed over and came to his own city.
2  And behold, some people brought to him a paralytic, lying on a bed. And when Jesus saw their faith, he said to the paralytic, “Take heart, my son; your sins are forgiven.” 
3  And behold, some of the scribes said to themselves, “This man is blaspheming.”
4  But Jesus, knowing their thoughts, said, “Why do you think evil in your hearts? 
5  For which is easier, to say, ‘Your sins are forgiven,’ or to say, ‘Rise and walk’? 
6  But that you may know that the Son of Man has authority on earth to forgive sins”—he then said to the paralytic—“Rise, pick up your bed and go home.” 
7  And he rose and went home.
8  When the crowds saw it, they were afraid, and they glorified God, who had given such authority to men.