Zechariah 14:3-4

14:3 Then the Lord will go to battle and fight against those nations, just as he fought battles in ancient days. 14:4 On that day his feet will stand on the Mount of Olives which lies to the east of Jerusalem, and the Mount of Olives will be split in half from east to west, leaving a great valley. Half the mountain will move northward and the other half southward.