Mark 2:8-9

Only God can heal and forgive sins. These actions are equally impossible to men. However a person cannot verify his claim to forgive sins, but his claim to be able to heal paralysis is verifiable. The scribes therefore assumed that the claim to heal paralysis was the greater one. Jesus frequently used the rabbinic device of asking counter questions, especially when dealing with opponents (cf. Mark 3:4; Mark 11:30; Mark 12:37).