|Jesus Teaches in the Temple by James Tissot|
Here is an interesting answer to the question of where Jesus offered his “High Priestly” prayer in John 17, on the night of his arrest. B. F Westcott, says it was NOT in the upper room, because Jn. 14:31 says Jesus took them out of that room at this point. His argument made a lot of sense to me:
“It is scarcely possible that [John] chapters xv., xvi. could have been spoken in the streets of the city. It is inconceivable that ch. xvii, should have been spoken anywhere except under circumstances suited to its unapproachable solemnity. The character of the descent to the Kidron, and of the ground on the western side, does not afford a suitable locality. The upper chamber was certainly left after xiv. 31. One spot alone, as it seems, combines all that is required to satisfy the import of these last words, the Temple courts. It may be true that there is nothing in the narrative which points immediately to a visit there; but much in what is recorded gains fresh significance if regarded in connexion (sic) with the seat of old worship. The central object was the great Golden Vine (comp. Fergusson, ‘The Temples of the Jews,’ pp. 151-ff.), from which the Lord derived the figure of His own vital relation to His people. Everything which spoke of a divine Presence gave force to the promise of a new Advocate. The warning of persecution and rejection found a commentary in the scenes with which the temple had been associated in the last few days. Nowhere, as it seems, could the outlines of the future spiritual Church be more fitly drawn than in the sanctuary of the old Church. Nowhere it is clear, could our High Priest more fitly offer His work and Himself and believers to the Father, than in the one place in which God had chosen to set His Name.”
B. F. Westcott, The Gospel According to St. John, (Grand Rapids: Wm. B. Eerdmans Publishing Co., 1978), p. 237.
As to the availability of the Temple late at night, Westcott points out that Josephus says they opened the temple gates at midnight during the Passover season. See, Josephus, Antiquities of the Jews, 18, 2, 2.