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Chapter 22.

30. That the place of baptism is sometimes supplied by martyrdom is supported by an argument by no means trivial, which the blessed Cyprian adduces from the thief, to whom, though he was not baptized, it was yet said, "Today shall you be with me in Paradise." Luke 23:43 On considering which, again and again, I find that not only martyrdom for the sake of Christ may supply what was wanting of baptism, but also faith and conversion of heart, if recourse may not be had to the celebration of the mystery of baptism for want of time. For neither was that thief crucified for the name of Christ, but as the reward of his own deeds; nor did he suffer because he believed, but he believed while suffering. It was shown, therefore, in the case of that thief, how great is the power, even without the visible sacrament of baptism, of what the apostle says, "With the heart man believes unto righteousness, and with the mouth confession is made unto salvation." Romans 10:10 But the want is supplied invisibly only when the administration of baptism is prevented, not by contempt for religion, but by the necessity of the moment. For much more in the case of Cornelius and his friends, than in the case of that robber, might it seem superfluous that they should also be baptized with water, seeing that in them the gift of the Holy Spirit, which, according to the testimony of holy Scripture, was received by other men only after baptism, had made itself manifest by every unmistakable sign appropriate to those times when they spoke with tongues. Yet they were baptized, and for this action we have the authority of an apostle as the warrant. So far ought all of us to be from being induced by any imperfection in the inner man, if it so happen that before baptism a person has advanced, through the workings of a pious heart, to spiritual understanding, to despise a sacrament which is applied to the body by the hands of the minister, but which is God's own means for working spiritually a man's dedication to Himself. Nor do I conceive that the function of baptizing was assigned to John, so that it should be called John's baptism, for any other reason except that the Lord Himself, who had appointed it, in not disdaining to receive the baptism of His servant, Matthew 3:6, 13 might consecrate the path of humility, and show most plainly by such an action how high a value was to be placed on His own baptism, with which He Himself was afterwards to baptize. For He saw, like an excellent physician of eternal salvation, that overweening pride would be found in some, who, having made such progress in the understanding of the truth and in uprightness of character that they would not hesitate to place themselves, both in life and knowledge, above many that were baptized, would think it was unnecessary for them to be baptized, since they felt that they had attained a frame of mind to which many that were baptized were still only endeavoring to raise themselves.

CHURCH FATHERS: On Baptism, Book IV (Augustine) (newadvent.org)

In the fourth book, when I said: "Suffering can take the place of baptism,” 5 I cited the example of the thief, which is not quite appropriate, for it is uncertain whether he had been baptized

Augustine Retractations : St Augustine : Free Download, Borrow, and Streaming : Internet Archive

Here's the sole retraction regarding the very section at issue cited above:

Where's the "retraction" of BOD? For the sake of truth and being accurate, he's simply correcting a statement about the good thief, since in his case "it is uncertain whether he has been baptized." That's it.

If St. Augustine indeed "retracted" a support of BOD, that would have been the time, while scrutinizing error in the very section where he supported BOD.

He didn't retract his support of the concept.