"Have not I chosen you twelve, and one of you is a devil?"
For since Peter said, "We believe," Jesus excepteth Judas from the band. In the other place Peter made no mention of the disciples; but when Christ said, "Whom say ye that I am?" he replied, "Thou art the Christ, the Son of the living God"; but here, since he said, "We believe," Christ with reason admitteth not Judas into that band. And this He did afar off, and long before the time, to check the wickedness of the traitor, knowing that He should avail nothing, yet doing His own part.
For since Peter said, "We believe," Jesus excepteth Judas from the band. In the other place Peter made no mention of the disciples; but when Christ said, "Whom say ye that I am?" he replied, "Thou art the Christ, the Son of the living God"; but here, since he said, "We believe," Christ with reason admitteth not Judas into that band. And this He did afar off, and long before the time, to check the wickedness of the traitor, knowing that He should avail nothing, yet doing His own part.
Source: Homily on the Gospel of John 47