John Chrysostom

(Hom. i. in Act.) Further, lest any should say that abandoning their acquaintances they went to show themselves, (or as it were to vaunt themselves with a kind of pomp,) to strangers, therefore first among the very murderers themselves are the signs of the resurrection displayed, in that very city wherein the frantic outrage burst forth. For where the crucifiers themselves are seen to believe, there the resurrection is most of all demonstrated.

(Hom. i. in Act.) But as a general does not permit his soldiers who are about to meet a large number, to go out until they are armed, so also the Lord does not permit His disciples to go forth to the conflict before the descent of the Spirit. And hence He adds, But tarry ye in the city of Jerusalem, until ye be endued with power from on high.

(ut sup.) But why did not the Spirit come while Christ was present, or immediately on His departure? Because it was fitting that they should become desirous of grace, and then at length receive it. For we are then most awakened towards God, when difficulties press upon us. It was necessary in the mean time that our nature should appear in Heaven, and the covenants be completed, and that then the Spirit should come, and pure joys be experienced. Mark also what a necessity He imposed upon them of being at Jerusalem, in that He promised that the Spirit should there be given them. For lest they should again flee away after His resurrection, by this expectation, as it were a chain, He kept them all there together. But He says, until ye be endued from on high. He did not express the time when, in order that they may be constantly watchful. But why then marvel that He does not reveal to us our last day, when He would not even make known this day which was close at hand.

Or He said, Receive ye the Holy Spirit, that He might make them fit to receive it, or indicated as present that which was to come.