Acts XXII. 17-20
“And it came to pass, that, when I had come again to Jerusalem, even while I prayed in the temple, I was in a trance; and saw him saying unto me, Make haste, and get you quickly out of Jerusalem: for they will not receive your testimony concerning me. And I said, Lord, they know that I imprisoned and beat in every synagogue them that believed on you: and when the blood of your martyr Stephen was shed, I also was standing by, and consenting unto his death, and kept the raiment of them that slew him.”
Source: Homilies on Acts (New Advent)