Augustine of Hippo, on Acts 2:37

“Now when they had heard these things, they had compunction in their heart, and said to Peter, and to the rest of the apostles: What shall we do, men and brethren?”

“For on the sending down of the Holy Spirit after the Lord's passion, and resurrection, and ascension, when miracles were being done in the name of Him whom, as if dead, the persecuting Jews had despised, they were pricked in their hearts; and they who in their rage slew Him were changed and believed; and they who in their rage shed His blood, now in the spirit of faith drank it; to wit, those three thousand, and those five thousand Jews whom now He saw there, when He said, "When ye have lifted up the Son of man, then shall ye know that I am [He]." It was as if He had said, I let your recognition lie over till I have completed my passion: in your own order ye shall know who I am. Not that all who heard Him were only then to believe, that is, after the Lord's passion; for a little after it is said, "As He spake these words, many believed on Him;" and the Son of man was not yet lifted up. But the lifting up He is speaking of is that of His passion, not of His glorification; of the cross, not of heaven; for He was exalted there also when He hung on the tree. But that exaltation was His humiliation; for then He became obedient even to the death of the cross. This required to be accomplished by the hands of those who should afterwards believe, and to whom He says, "When ye have lifted up the Son of man, then shall ye know that I am [He]." And why so, but that no one might despair, however guilty his conscience, when he saw those forgiven their homicide who had slain the Christ?”

Imported from an open dataset — not yet checked against the printed edition.