The man answered— Utterly illiterate as he was!—and with what strength and clearness of reason! Thus God had opened the eyes of his understanding, as well as his bodily eyes. "Why, herein is a marvellous thing, that ye,—the teachers and guides of the people, should not know that a man, who hath wrought a miracle, the like of which was never heard of before must be from heaven, sent by God; for we, even we of the populace, know that God heareth not sinners, so as to answer their prayers in this manner." This indeed was a truth universally allowed: now they all knew that God had heard Jesus by the work that he had wrought, which had been confirmed beyond any possibility of doubt: therefore it followed by plain consequence, that Jesus was not a sinner, but of God, since otherwise he could do nothing. This argument was irrefragable.
Related Commentaries of John 9:30
John 9:30-31
30 The man answered and said unto them, Why herein is a marvellous thing, that ye know not from whence he is, and yet he hath opened mine eyes.
31 Now we know that God heareth not sinners: but if any man be a worshipper of God, and doeth his will, him he heareth.