John 9:25
He answered and said, Whether he be a sinner or no, I know not: one thing I know, that, whereas I was blind, now I see.
Cross-reference
John 9:30
Parallel
In John 9:30, the healed man expands his testimony, marveling that the Pharisees don't know where Jesus comes from despite his miracle.
John 9:39
Prophetic fulfillment
In John 9:39, Jesus declares his mission to give sight to the blind — the blind man's testimony here is the literal fulfillment of that purpose.
John 5:11
Parallel
In John 5:11, the healed paralytic simply states what Jesus told him; similarly here the blind man states his simple experience — both face opposition.
John 5:15
Parallel
In John 5:15, another healed man reports Jesus to the authorities — similar act of testimony, though the blind man's testimony is more defiant.