His feet shall stand. By this theophany he shall come to the aid of his people; nature shall do his bidding, owning the presence of its Maker. Upon the Mount of Olives … on the east. This mount lay on the east of Jerusalem, from which it was separated by the deep valley of the Kidron, rising to a height of some six hundred feet, and intercepting the view of the wilderness of Judaea and the Jordan ghor.
The geographical detail is added in the text to indicate the line of escape which shall be opened for those who are to be de-livened. This is the only place in the Old Testament where the Mount of Olives is thus exactly named; but it is often alluded to; e.
g. 2 Samuel 15:30; 1 Kings 11:7; 2 Kings 23:13 (where it is called "the mount of corruption"), etc. Shall cleave in the midst thereof. As the enemy are supposed to beset Jerusalem, so as to make escape by any ordinary road impossible, the Lord will open a way through the very centre of the mountain (as he opened a path through the Red Sea), by cleaving the hill in sunder, the two parts moving north and south, and leaving a great valley running east and west, and leading to the Arabah.