Here is the oration that the Church prays in the Mass and Office for Sunday after the Ascension:
Omnípotens sempitérne Deus: fac nos tibi semper et devótam gérere voluntátem; et majestáti tuæ sincéro corde servíre.
Here is my translation:
O almighty and sempiternal God, make us always both to conduct our will in a manner devoted to Thee, and to serve Thy majesty with a sincere heart.
Here is the translation from the Divinum Officium site:
Almighty and eternal God, give us a will ever dedicated to You, and a true heart to serve Your majesty.
We are in that Sunday that stands between the triumphant Ascension of Jesus Christ into Heaven and the promised coming of the Paraclete at Pentecost. We are “seeking the face” of the Holy Ghost (see the Introit of today’s Mass), who will come to strengthen our wills and make our hearts right. He Himself is the gift of God the most high, who brings with Him that sevenfold complement of operative habits we call the “gifts of the Holy Ghost” in order to perfect our virtues, which, in turn, perfect us.
Saint Thomas says that the giving of the Holy Ghost is the essence of the New Law, which is only secondarily a written law.
All the forgoing is said to lay a foundation for this observation: Today’s oration, while it seems quite “generic,” as a prayer for us to have wills devoted to God and hearts that serve His majesty, should be seen against the backdrop of the mission of the Holy Ghost.
In today’s Epistle (1 Pet. 4:7-11) Saint Peter exhorts us to practice charity towards each other, serving each other and speaking to each other as administering God’s grace to each other — “as good stewards of the manifold grace of God.” What we receive in our hearts and wills from the Holy Ghost ought to be ministered by us to our neighbor for his edification and uplifting. We must, in short, help each other to love God and to arrive safely at the port of salvation. It is the mission of the Sanctifier to achieve that, building as He does on the saving mission of the Son.
The faith teaches us that the eternal procession of the Son from the Father is one of the intellect, that is of knowing (He is the Logos), whereas the procession of the Holy Ghost from the Father and the Son is one of willing — it is a motion of love. For this reason, the Holy Ghost is called Substantial Charity, or Love in Person. The petition that God make our wills ever devoted to Himself in today’s collect seems especially apt in light of this, as is mention of sincerity of heart, which is the organ that stands as the symbolic epicenter of love.
Our Lord speaks of the coming of the Holy Ghost in the Gospel (John 15:26-27; 16:1-4). Jesus tells the Apostles that He will send them the Paraclete from the Father, and that this same Paraclete will give testimony of Jesus just as the Apostles themselves will give testimony of their Master. He says this to prevent them from being “scandalized” when men turn against them and kill them, thinking that they are doing a service to God.
This twofold testimony of the Advocate and the Apostles is related to our collect. Jesus is preparing the Apostles for the ultimate testimony they will give of Him: the terminus and perfecting of their apostolate by martyrdom. It is the Holy Ghost who will strengthen the Apostles to carry on their mission even unto death. Moreover, it is He that will move to faith, hope, and charity those who hear the Apostles preach and witness their martyrdom. In fine, both the Apostles and those who efficaciously hear their testimony will be moved to conduct their wills in a manner devoted to God, and to serve His majesty with sincere hearts.