The opening of the eyes of the blind without the application of means rationally probable for the producing such an effect, nay, by the application of means which to all human reason seemed of a quite contrary tendency; and this cure wrought upon one who was not blind by some accidental cause, but by some defect in nature, who had been so from his mother's womb, was so manifest an effect of the Divine power, as this poor man was astonished at it, that they should not understand that it was done by such a power, either immediately or mediately; especially considering the prophecy concerning the Messias, Isaiah 35:5,6, to which Christ refers John and his disciples for an evidence of it, Matthew 11:5.
Related Commentaries of John 9:30
John 9:30
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.