John Chrysostom — as excerpted in the Catena Aurea on John 14:27-31

“(Hom. lxxv. 4) Or thus: The Apostles did not yet know what the resurrection was of which He spoke when He said, I go, and come again to you; or what they ought to think of it. They only knew the great power of the Father. So He tells them: Though ye fear I shall not be able to save Myself, and do not trust to My appearing again after My crucifixion; yet when ye hear that I go to My Father, ye should rejoice, because I go to one greater, one able to dissolve and change all things. All this is said in accommodation to their weakness: as we see from the next words; And now I have told you before it come to pass; that when it does come to pass, ye may believe.”