John 9: 26-29.
Then said they to him again, What did He to thee? how opened He thine eyes?
He answered them, I have told you already, and ye did not hear: wherefore would ye hear it again? will ye also be His disciples?
Then they reviled him, and said, Thou art His disciple; but we are Moses’ disciples.
We know that God spake unto Moses: as for this fellow, we know not from whence He is.

So, why did the Pharisees question the blind man yet again?
It’s a proven interrogation technique. If you make a person tell his story several times, there’s a good chance he’s going to contradict himself if he’s not telling the truth. The Pharisees were determined to discredit his story.
What I love about this particular passage is that the blind man did not answer them by repeating his story. Instead, he said, (my own paraphrase) “Look. I’ve already told you what happened. I’ve told you the truth! You didn’t really believe me before, so why are you asking again? Do you want to become His disciples?” The blind man was clearly not stupid. He was even capable of a little sarcasm, and must have known he was risking punishment when he asked the Pharisees if they were interested in becoming followers of Jesus.
I think the Pharisees must have been steaming by this time. They reviled the blind man, saying, “YOU may be His disciple; WE, however, are MOSES’ disciples!”
One might ask, at this point, if they realized who they were claiming to worship: God, or Moses? Moses never asked or wanted to be worshiped or treated as God. He was not the creator of the Law; he was only the messenger whom God chose to bring the Law to the people. If the Pharisees worshiped God, surely they would have known, by their diligent study of the scriptures, that Jesus was something special! Indeed, they worshiped the Law more than they worshiped the Creator of the Law!
At least they acknowledged that God spoke to Moses. I want you to notice in verse 29 that in the second half of the verse, the words as for . . . fellow are italicized. That indicates that those three words were interpolated for clarity. If we omit them, that part of the verse would read, “This? We don’t know anything about Him!”
Do you see how disparaging their language was? They reviled not only the blind man, but also the Son of Man, referring to Him as if He were nothing at all. I can imagine them making dismissive gestures, shaking their heads, maybe even rolling their eyes at the worthlessness of Jesus, Whom they did not know and did not want to know. Part of the reason they hated Him so much was that so many of the people were amazed at His works and His words, and were actually following Him from place to place and spending time listening to His teaching.
They couldn’t tolerate it. Their authority was in question, and that had to stop!