Contradiction with Mark 13:23
Jesus warns his disciples about future events, indicating similar foresight as in John 16:4, not a contradiction.
Mark 13:23: But take ye heed: behold, I have foretold you all things.
Contradiction with John 14:29
This verse, like John 16:4, mentions Jesus predicting events before they occur, showing consistency rather than contradiction.
John 14:29: And now I have told you before it come to pass, that, when it is come to pass, ye might believe.