John Chrysostom — as excerpted in the Catena Aurea on John 14:22-27

“(Hom. lxxv. 3) To enable them to sustain His bodily departure more cheerfully, He promises that that departure shall be the source of great benefit; for that while He was then in the body, they could never know much, because the Spirit would not have come: But the Comforter, which is the Holy Ghost, Whom the Father will send in My name, He shall teach you all things, and bring all things to your remembrance, whatsoever I have said unto you.”