John 9:12
Then said they unto him, Where is he? He said, I know not.
Cross-reference
John 5:11–13
Parallel
In John 5:11-13, the healed man at Bethesda doesn't know who healed him—parallel to the blind man's 'I do not know' here.
John 5:15
Parallel
In John 5:15, another healed man reports Jesus to the authorities — both testify despite potential backlash.