John Calvin on John 9:25

25. Whether he be a sinner, I know not. The blind man appears not to have been at all prevented by fear from giving a sincere testimony. For there is no reason to believe that he had any doubts about Christ, as his words seem to imply; but I rather think that he spoke ironically, in order to wound them more deeply. He had already confessed that Christ was a Prophet, (verse 17.) Perceiving that he gains nothing by doing so, he suspends his judgment about the person, and brings forward the fact itself, so that, while he makes this admission in their favor, he is not free from ridiculing them.