John 9:5 - Coke's Commentary on the Holy Bible

As long as I am in the world, &c.— Because our Lord was going to confer sight on a man who was born blind, he thence took occasion to speak of himself, as one appointed to give light likewise to the darkened minds of men. Hence we learn that our Lord's miracles were designed, not only as proofs of his mission, but to be specimens of the power which he possessed as Messiah. For example, by feeding the multitude with meat that perished, he signified that he was come to quicken and nourish mankind with the bread of life, that sovereign cordial and salutary nutriment of the soul. His giving sight to the blind was a lively emblem of the efficacy of his doctrines, to illuminate the blinded understandings of men. His healing their bodies, represented his power to heal their souls; and was a specimen of his authority to forgive sins, as it was a real, though but a partial removal of the punishment of sin. His casting out devils, was an earnest of his final victory over Satan and all his associates. His raising particular persons from the dead, was the beginning of his triumphs over death, and a demonstration of his ability to accomplish a general resurrection;and,togivenomoreexamples,hiscuringall promiscuously who applied to him, shewed that he was come not to condemn the world, but to save even the chief of sinners. Accordingly, at performing these miracles, or soon after, while the memory of them was fresh in the minds of his hearers, we often find him turning his discourse to the spiritual things which were signified by them, as in the case before us. See the Inferences on Matthew 9.