What does John 9:33 mean?

When Jesus healed a man born blind, His religious critics responded in a predictable way. Jesus had already challenged them for willful ignorance (John 7:17), and for "refusing" to follow their own Scriptures in order to believe in Him (John 5:39–40). Here, these men have twice interrogated the healed man (John 9:13, 24), looking for any reason to dismiss Jesus' work. The formerly-blind beggar, for his part, responded with bravery and remarkably clear thinking. His overall point, delivered with heavy sarcasm, has been that Jesus' miracles themselves ought to be evidence enough that He's been sent by God.

Here, the healed man makes this statement in clear and direct terms. This is almost identical to the conclusion Nicodemus brought to Jesus earlier in the gospel of John (John 3:1–2). This verse is the summary of the man's response to the insults of the scribes and Pharisees, who tried to reject Jesus as a "sinner" instead of accepting His miracles.

At this point, the religious leaders of Jerusalem have been thoroughly embarrassed. They have failed to debunk Jesus' miracle. They have responded in angry insults to one of their witnesses. And, they've been "taught" some common sense spiritual truth by a man they consider beneath them.

The following verse is exactly the kind of reaction one would expect from these kinds of spiritual hypocrites. Rather than countering the man's argument, or challenging his facts, they resort once again to insults.