Roman Catechism 8.18

Chapter 8 — Part I: The Creed — Article VI: He Ascended into Heaven, Sitteth at the Right Hand of God, the Father Almighty

Section 18. Results Of The Ascension — The extent and greatness of the unutterable blessings which the bounty of God has showered on us were long before, as the Apostle interprets, sung by the inspired David: Ascending on high, he led captivity captive: He gave gifts to men.' For on the tenth day He sent down the Holy Ghost, with whose power and plenitude He filled the multitude of the faithful then present, and so fulfilled that splendid promise: It is expedient to you that I go: for if I go not, the Paraclete will not come to you; but if I go, I will send him to you.