The Destruction of the Temple Foretold, part 1
And as he came out of the temple, one of his disciples said to him, "Look, Teacher, what wonderful stones and what wonderful buildings!" And Jesus said to him, "Do you see these great buildings? There will not be left here one stone upon another, that will not be thrown down."
Bede, in Marc., iv, 42 - Because after the founding of the Church of Christ, Judaea was to be punished for her treachery, the Lord fitly, after praising the devotedness of the Church in the person of the poor widow, goes out of the temple, and foretold its coming ruin, and the contempt in which the buildings now so wonderful were soon to be held.
Wherefore it is said, "And as He went out of the temple, one of His disciples saith unto Him, Master, see what manner of stones and what buildings are here!"
Theophylact - For, since the Lord had spoken much concerning the destruction of Jerusalem, His disciples wondered, that such numerous and beautiful buildings were to be destroyed; and this is the reason why they point out the beauty of the temple, and He answers not only that they were to be destroyed, but also that one stone should not be left upon another.
Wherefore it goes on: "And Jesus answering said unto him, Seest thou these great buildings? there shall not be left one stone upon another, that shall not be thrown down."
Now some may endeavour to prove that Christ's words were false, by saying that many ruins were left, but this is not at all the point; for though some ruins had been left, still at the consummation of all things one stone shall not be left upon another. Besides it is related, that Aelius Adrian overturned the city and the temple from the foundation, so that the word of the Lord here spoken was fulfilled.
Bede - But it was ordered by Divine power that after that the grace of the faith of the Gospel was made known through the world, the temple itself with its ceremonies should be taken away; lest perchance some one weak in the faith, if he saw that these things which had been instituted by God still remained, might by degrees drop from the sincerity of the faith, which is in Christ Jesus, into carnal Judaism.
Pseudo-Jerome - Here also the Lord enumerates to His disciples the destruction of the last time, that is of the temple, with the people, and its letter; of which one stone shall not be left upon another, that is, no testimony of the Prophets upon those, to whom the Jews perversely applied them, that is, on Ezra, Zerubbabel and the Maccabees.
Bede - Again, when the Lord left the temple, all the edifice of the law and the framework of the commandments were destroyed, so that nothing could be filled up by the Jews; and now that the head has been taken away, all the limbs fight one against the other.
- text taken from Catena Aurea - Gospel of Mark by Saint Thomas Aquinas, translated by William Whiston, 1842