Augustine, On Baptism, Against the Donatists 4.22
Augustine will not pretend the Gospels record the thief’s baptismal history. He treats the case as conversion of heart when water was no longer possible — not as proof that people who can still walk to the water may skip it.
The oldest Christian file on this verse does not say ‘he was unbaptized, therefore baptism is optional.’ It says we do not know, and that Christ can save a dying man. That is not a repeal of John 3:5.

