Luke 19:44

And shall lay thee even with the ground, and thy children within thee; and they shall not leave in thee one stone upon another. That is, shall destroy thee utterly; spoken in hyperbole, for the Romans were not so laborious or so idle, as to leave no stone upon another. S. Greg., hom. xxxix. The migration from the city is testified to, for it is now built on the spot where the Lord was crucified outside the gate. The former Jerusalem is utterly destroyed; for Mount Calvary is now in the middle of the new city.

Because thou knowest not the time of thy visitation. "The time of this visitation," says Titus, "is that of Christ's coming down from heaven." "In figure all these things," says S. Gregory hom. 39, "happen to the soul that has lived as a slave to the flesh. For then the devils surround it on all sides, tempt it, hedge it in, and carry it off to hell. Then all that erection of stones, that is, their thoughts, is overthrown, because they did not know the time of their visitation, when God by His preachers, His confessors, His masters, and His internal inspirations, warned them to amend their lives and take thought for their salvation." Greg ., Dial. Bk. iv chaps. 30, 38, 46, 52, and following, gives the dreadful example of Chrysaorius Theodore, King Theodoric, and others.