Augustine of Hippo
Catena Aurea · Matthäusevangelium 12
Wherefore I say unto you, All manner of sin and blasphemy shall be forgiven unto men: but the blasphemy against the Holy Ghost shall not be forgiven unto men. And whosoever speaketh a word against the Son of man, it shall be forgiven him: but whosoever speaketh against the Holy Ghost, it shall not be forgiven him, neither in this world, neither in the world to come.
(Retract. i. 19.) But I do not affirm this for certain, by saying that I think thus; yet thus much might have been added; If he should close this life in this impious hardness of heart, yet since we may not utterly despair of any however evil, so long as he is in this life, so neither is it unreasonable to pray for him of whom we do not despair.