But that ye may know that the son of man
Meaning himself, who was really man, and the true Messiah, in which sense this phrase had been used in the writings of the Old Testament; see ( Psalms 80:17 ) ( Daniel 7:13 ) , and though by reason of his outward form; and mean appearance, he might be thought by them to be but a mere man, and had no right, nor authority, to say what he had; in order to convince them; he affirms, that he
hath power on earth to forgive sins.
As there is an emphasis lies on the phrase, "the son of man", suggesting, that his being so was no contradiction to his deity, nor any hindrance to the exertion of his power; so there is another on those words, "upon earth"; intimating, that though he was upon earth, in a very low estate, in a state of humiliation, yet he had the same power to forgive sin as in heaven; his humbling himself in human nature did not strip him of his perfections, power, and prerogative as God: and if he had power on earth to forgive sin, there can be no room to doubt of it now he is in heaven; since as mediator, he is "exalted to be a prince, and a Saviour, to give repentance to Israel, and remission of sins", ( Acts 5:31 ) , And that it might appear he had such a power on earth,
he saith to the sick of the palsy;
turning to, and addressing him in the following words, with great majesty, authority, and power; (See Gill on Matthew 9:6).