Of one possessed with a demon (δαιμονιζομενου). Genitive of present passive participle of δαιμονιζω. They had heard demoniacs talk, but not like this.

Can a demon open the eyes of the blind? (μη δαιμονιον δυνατα τυφλον οφθαλμους ανοιξαι;). Negative answer expected. Demons would more likely put out eyes, not open them. It was an unanswerable question.