The former account I made, O Theophilus, of all that Jesus began both to do and teach, until the day in which He was taken up, after He through the Holy Spirit had given commandments to the apostles whom He had chosen, to whom He also presented Himself alive after His suffering by many infallible proofs, being seen by them during forty days and speaking of the things pertaining to the kingdom of God. And being assembled together with them, He commanded them not to depart from Jerusalem, but to wait for the Promise of the Father, “which,” He said, “you have heard from Me; for John truly baptized with water, but you shall be baptized with the Holy Spirit not many days from now. Therefore, when they had come together, they asked Him, saying, “Lord, will You at this time restore the kingdom to Israel?” And He said to them, “It is not for you to know times or seasons which the Father has put in His own authority. But you shall receive power when the Holy Spirit has come upon you; and you shall be witnesses to Me in Jerusalem, and in all Judea and Samaria, and to the end of the earth. Now when He had spoken these things, while they watched, He was taken up, and a cloud received Him out of their sight. And while they looked steadfastly toward heaven as He went up, behold, two men stood by them in white apparel, who also said, “Men of Galilee, why do you stand gazing up into heaven? This same Jesus, who was taken up from you into heaven, will so come in like manner as you saw Him go into heaven.” Then they returned to Jerusalem from the mount called Olivet, which is near Jerusalem, a Sabbath day’s journey.
Fr. Lev Gillet comments on the Ascension:
“Jesus does not return to his Father in isolation. It was the incorporeal Logos that descended among men. But today it is the Word made flesh, at the same time true God and true man, that enters the Kingdom of heaven. Jesus takes there with him the human nature in which he is clothed. He opens the gates of the Kingdom to humanity. We take possession, in some way by anticipation of the blessings which are offered to us and possible for us. Places are reserved for us in the Kingdom provided we continue faithful. Our presence is desired and awaited there. So the ascension renders the thought of heaven more present and more alive for us. Do we think enough of our permanent dwelling-place? For most Christians heaven is envisaged as a kind of postscript, an appendix to a book of which life on earth constitutes the actual text. But the contrary is true. Our earthly life is merely the preface to the book. Life in heaven will be the text – a text without end.” (A Monk of the Eastern Church in The Time of the Spirit: Readings Through the Christian Year, p 162)