Here is the oration that the Church prays in the Mass and Office for the Feast of the Ascension:
Concéde, quǽsumus, omnípotens Deus: ut, qui hodiérna die Unigénitum tuum, Redemptórem nostrum, ad cœlos ascendísse crédimus; ipsi quoque mente in cœléstibus habitémus.
Here is my translation:
Almighty God, grant, we ask Thee, that we who believe Thy Only-Begotten Son, our Redeemer, to have mounted up to Heaven on this day, may dwell in spirit with Him in the heavenly places.
Here is the translation from the Divinum Officium site:
Grant, we beseech thee, Almighty God, that like as we do believe thine Only-Begotten Son our Saviour to have this day ascended into the heavens, so we may also in heart and mind thither ascend, and with Him continually dwell.
This prayer is a beautiful illustration of the tropological sense of Holy Scripture. While this word is explained here, and applied concretely to today’s feast here, in summary, we can say that it is the “turning” or application of a Biblical passage back upon us, the reader. In this beautiful oration, while fully appreciating the literal, historical truth of the bodily Ascension of Jesus Christ into Heaven — the proper subject-matter of today’s feast — we apply the meaning of this Christological Mystery to ourselves in such a way that we desire to mount thither with Him spiritually. Doing so in this life is a prelude to our own bodily rising up into Heaven at the last day if we persevere to the end in faith, hope, and charity.
As members of the Mystical Body of Jesus Christ, each of us in the locus of a Mystical Incarnation that it is the very purpose of the Christian life. For this reason, as Dom Marmion would say, “Christ’s Mysteries are our mysteries.”
A most happy Feast-Day to all!