John 14-16 records Jesus’ Final Discourse with the disciples prior to the events of Gethsemane. At John 14:31 we read, “But that the world may know that I love the Father, and as the Father gave Me commandment, so I do. Arise, let us go from here.” The discourse continues and then John 17 records Jesus’ high-priestly prayer. Then John 18:1 states, “When Jesus had spoken these words, He went out with His disciples over the Brook Kidron, where there was a garden, which He and His disciples entered.”
In his classic A Harmony of the Gospels, A.T. Robertson notes on John 14:31, “Apparently they leave the Upper Room” and entitles the section continuing in John 15 and 16, “The Discourse on the Way to Gethsemane,” with the subtitle, “Possibly on the Street.”
It is possible that Jesus and His disciples rose up immediately at John 14:31, and that the continued discourse and prayer of chapters 15-17 occurred en route from the Upper Room on the way to Gethsemane. Others suggest that the short time required for Jesus’ teaching of chapters 15-16 and the prayer of chapter 17 can better fit within that Upper Room setting. That would not be unlike our saying, I [we] need to be going now, and yet a few more minutes of conversation take place before the actual departure.
J.W. McGarvey observes, “Some think that Jesus then left the room, and that the next three chapters of John’s Gospel contain matters spoken on the way to Gethsemane. But it is likely that the words of these chapters were spoken in the upper room after they had risen from the table and prepared to depart, and that John 18:1 marks the leaving of the upper room as well as the crossing of the Kidron”(The Four-Fold Gospel.667).
Lenski goes into a bit more detail in his remarks:
Nevertheless … arise, let us be going hence” ends the Passover feast. No destination is indicated, yet the disciples know that Jesus intends to meet “the world’s ruler” and thus once more do the Father’s ἐντολή. The asyndeton ἐγείρεσθε ἄγωμεν is idiomatic, as is also the combination of the present imperative with the hortative present subjunctive. The action of arising from the couches on which the company had dined is merely preliminary to the action of leaving the place and going elsewhere. Those who regard “Arise,” etc., as a separate sentence incline to the opinion that Jesus left the upper room at this point, spoke the next three chapters somewhere on the way to the Kidron, crossed this at 18:1, and then went on to Gethsemane. When we note that the bidding to arise and to leave is only the conclusion of a longer sentence, that 15:1, etc., indicates no change of place, and that ἐξῆλθεν in 18:1 reads as though Jesus did not leave the upper room until that moment, we are led to conclude that after the company arose from their couches they lingered in the upper room until Jesus finished speaking the next three chapters. This delay consumed only a short time. We cannot think that the next three chapters were spoken while the company was in motion, and John nowhere indicates that they halted at some spot along the way (Lenski, R. C. H. The Interpretation of St. John’s Gospel.1023–1024).
William Hendriksen notes:
Why not assign to these words their most natural meaning, and interpret them as actually amounting to a command that the disciples get up from their couches, coupled with an exhortation meaning, “And let us go away from here, that is, from this Upper Room; hence, from this house”? That still would not imply that the little company now immediately rushes out of the house! How often does it not happen even among us Westerners that between the exhortation, “Now let us be going,” and the actual departure there is a period of ten minutes? During that ten minutes a great deal can be said. Now, the following must be borne in mind:
a. In this very context Jesus clearly implies that there are still certain things which he wishes to say to the disciples (14:30).
b. Speaking calmly and deliberately, without any attempt to rush himself, Jesus may have uttered the contents of chapters 15, 16, and 17 within a period of ten minutes! When a company has been together for several hours, what is ten minutes? . . .
Accordingly, we shall proceed upon the assumption that the contents of chapters 14–17 comprise a unit, and that all of this was spoken that night in the Upper Room (Exposition of the Gospel According to John, Vol. 2.290–291).
In 2012 I posted an aerial photo of the Kidron here.