And his feet shall stand in that day upon the mount of Olives, which is before Jerusalem on the east, and the mount of Olives shall split in two, toward the east and toward the west, and there shall be a very great valley; and half of the mountain shall move toward the north, and half of it toward the south.
Read Chapter 14
Cyril of Jerusalem
AD 386
But it might happen that he should sit upon a foal; give us rather a sign where the king who enters will stand. Give us a sign not far from the city, that it may not be unknown to us; give us a sign nearby and clearly visible, that being in the city we may behold the place. Again the prophet answers, saying, “That day his feet shall rest upon the Mount of Olives, which is opposite Jerusalem to the east.” Is it possible for anyone standing within the city not to behold the place? Catechetical Lecture
Olives. Here the tenth legion was stationed, (Josephus, Jewish Wars vi. 3.) on the spot where Christ had denounced this judgment, and ascended into heaven, Luke xix. 41., and Acts i. 12.
South. We cannot show the literal accomplishment. If it regard the latter times, this must be hidden. But it suffices that some great earthquake should take place, according to most interpreters; or rather, (Calmet) the Romans removed vast quantities of earth and stone. (Josephus, Jewish Wars vi. 12.) (Grotius)
Olivet has three tops; the southern one is the lowest. But whether this was caused by an earthquake we know not. The rocks are said to split, when God displays his power and affords some miraculous assistance, Psalm xvii. 8., and Isaias xxiv. 8., and Habacuc iii. 10.