1 When the grand and lengthened discourse was concluded which the Lord delivered after supper, and on the eve of shedding His blood for us, to the disciples who were then with Him, and had added the prayer addressed to His Father, the evangelist John began thereafter the narrative of His passion in these words: “When Jesus had so spoken, He went forth with His disciples over the brook Cedron, where was a garden, into the which He entered, and His disciples. And Judas also, who betrayed Him, knew the place; for Jesus oft-times resorted there with His disciples.”
What he here relates of the Lord entering the garden with His disciples did not take place immediately after He had brought the prayer to a close, of which he says, “When Jesus had spoken these words:” but certain other incidents were interposed, which are passed over by the present evangelist and found in the others; just as in this one are found many things on which the others are similarly silent in their own narratives. But any one who desires to know how they all agree together, and the truth which is advanced by one is never contradicted by another, may seek for what he wants, not in these present discourses, but in other elaborate treatises; but he will master the subject not by standing and listening, but rather by sitting down and reading, or by giving his closest attention and thought to one who does so.
Yet let him believe before he know, whether he be able also to come to such a knowledge in this life, or find it impossible through some existing entanglements, that there is nothing written by any one evangelist, as far as regards those who have been received by the Church into canonical authority, that can be contrary to his own or another's equally veracious narrative. At present, therefore, let us look at the narrative of the blessed John, which we have undertaken to expound, without any comparison with the others, and without lingering over anything in it that is already sufficiently clear; so that where it is needful to do so, we may the better answer the demand.
Let us, therefore, not take His words, “When Jesus had spoken these words, He went forth with His disciples over the brook Cedron, where was a garden, into the which He entered, and His disciples,” as if it were immediately after the utterance of these words that He entered the garden; but let the clause, “When Jesus had spoken these words,” bear this meaning, that we are not to suppose Him entering the garden before He had brought these words to a close.
Source: Tractates on the Gospel of John (New Advent)