Theophylact of Ohrid — as excerpted in the Catena Aurea on John 14:22-27

“The Holy Spirit then was both to teach and to bring to remembrance: to teach what Christ had forborne to tell His disciples, because they were not able to bear it; to bring to remembrance what Christ had told them, but which on account of its difficulty, or their slowness of understanding, they were unable to remember.”