John 13:27-30

Verse 27

Satan entered into him - He had entered into him before, and now he enters again, to strengthen him in his purpose of delivering up his Master. But the morsel was not the cause of this entering in; the giving of it only marks the time in which the devil confirmed Judas in his traitorous purpose. Some have thought that this morsel was the sacrament of the Lord's Supper: but this is an utter mistake.

That thou doest, do quickly - As if he had said: "Thou art past all counsel; thou hast filled up the measure of thy iniquity, and hast wholly abandoned thyself to Satan; I will not force thee to turn from thy purpose, and without this thou wilt not. Thy designs are all known to me; what thou art determined to do, and I to permit, do directly; delay not, I am ready."
Verse 29

Buy those things that we have need of against the feast - Calmet's observation here has weight so it. "The disciples who thought that our Lord had said this to Judas, knew well that on the day of the passover there was neither buying nor selling in Jerusalem. This, therefore, did not happen on the paschal evening; for the feast, according to the common opinion, must have begun the preceding evening, and Jesus have eaten the passover with his disciples the night before his death; but it appears to me, by the whole text of St. John, that the passover did not begin till the time in which our Lord expired upon the cross. It was then that they were sacrificing the paschal lambs in the temple. It is therefore probable that the apostles believed that Judas went to purchase a lamb, and the other necessary things for the evening, and for the day of the Passover." On this subject the reader is requested to consult the observations at the end of Matthew 26, where the subject is considered at large.

Give something to the poor - It is well known that our Lord and his disciples lived on public charity; and yet they gave alms out of what they had thus received. From this we learn that even those who live on charity themselves are expected to divide a little with those who are in deeper distress and want.
Verse 30

He - went immediately out: and it was night - He set off to Jerusalem from Bethany, which was about two miles distant; and, under the conduct of the prince of darkness, and in the time of darkness, he did this work of darkness.
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