The Mount of Olives (also known as Olivet), so called from the trees filled with olives on its sides, is a ridge on the eastern side of Jerusalem. It is separated from the city by the valley of Kidron. It is approximately a Sabbath-day's journey from Jerusalem (or less than half a mile or 2,000 cubits). The first mention of the Mount of Olives in the Bible is during King David's flight from Jerusalem due to the rebellion of Absalom (2Samuel 15:30).
The Mount of Olives plays a PIVOTAL role in the ministry of Jesus:
It was this location that Jesus, just a few days before his crucifixion, wept over the city of Jerusalem (Luke 19:37-44).
It was while leaving Jerusalem's temple for the mount of olives that Jesus predicted its TOTAL destruction (Matthew 24:1-2; Mark 13:1-2; Luke 21:5-6).
It was on this location that Jesus gave prophesies about the events to occur just before his second coming to earth and the completion of the age (Matthew 24:3-26:2; Mark 13:3-7; Luke 21:7-38)
Jesus led his disciples to the mount (the garden of Gethsemane lies at the foot of it) after his last Passover so that he could pray and await his betrayal by Judas (Matthew 26:30-56)
It was while walking to the mount after his last Passover that Jesus gave the parable of the True Vine (John 15:1-27). He also offered his final words of encouragement. (John 16:1-31) and states that the disciples will leave him (John 16:32-33)
Lastly, it was on the Mount of Olives, just 40 days after his resurrection (on May 18th, 30 A.D.) that Jesus met with the disciples for one last time. Just before his ascension he commissions the disciples to preach the gospel everywhere and tells them:
"Then He said to them, 'Thus it is written, and thus it was necessary for the Christ to suffer and to rise from the dead the third day, and that repentance and remission of sins should be preached in His name to all nations, beginning at Jerusalem. And you are witnesses of these things.
"'Behold, I send the Promise of My Father upon you; but tarry in the city of Jerusalem until you are endued with power from on high.' " (Luke 24:46-49, NKJV)
After he is done speaking Jesus blesses the disciples and ascends into heaven. As the disciples gaze at Jesus ascending out of their sight, two angels in white appear. The angels tell them that Jesus will come back to the earth, to the Mount of Olives, in the same way they saw him leave (Mark 16:19-20; Luke 24:50-53; Acts 1:6-11).