Augustine of Hippo
Catena Aurea · Johannesevangelium 20
And after eight days again his disciples were within, and Thomas with them: then came Jesus, the doors being shut, and stood in the midst, and said, Peace be unto you, Then saith he to Thomas, Reach hither thy finger, and behold my hands; and reach hither thy hand, and thrust it into my side: and be not faithless, but believing. And Thomas answered and said unto him, My Lord and my God. Jesus saith unto him, Thomas, because thou hast seen me, thou hast believed: blessed are they that have not seen, and yet have believed. And many other signs truly did Jesus in the presence of his disciples, which are not written in this book: But these are written, that ye might believe that Jesus is the Christ, the Son of God; and that believing ye might have life through his name.
(de Symb. ad Cat. ii. 8) He might, had He pleased, have wiped all spot and trace of wound from His glorified body; but He had reasons for retaining them. He shewed them to Thomas, who would not believe except he saw and touched; and He will shew them to His enemies, not to say, as He did to Thomas, Because thou hast seen, thou hast believed, but to convict them: Behold the Man whom ye crucified, see the wounds which ye inflicted, recognise the side which ye pierced, that it was by you, and for you, that it was opened, and yet ye cannot enter there.