In this verse the Lord identifies himself with a remarkable name. He calls himself the Son of Man.
This links to what the scribes said when they spoke of this man
(Mark 2:7): they treat Jesus solely as a man. Although he lets them notice his divinity (Mark 2:8 - he knows their thoughts), he continues to stand before them as a mere man. This sharpens the tension. Only God can forgive, but the man Jesus is competent to do this on earth.
However, he is not just any man (this man
). He is the Son of the man. This does not mean something like human being
(for then it would say son of men
). It means that Jesus is the (promised) son of the man Adam. He is the son of Adam who would come and who will deliver (Genesis 3:15). And therefore, though a man, he has divine rights on earth. He is the beloved of God and God is well pleased with him (Mark 1:11). He is God’s Son as Adam’s son, and he is favoured by Israel’s God!1
10 But that you may know that the Son of Man has authority on earth to forgive sins” he said to the paralytic