13 Jesus therefore went up into heaven, and fulfilled the promise. For He said to them, I will pray the Father, and He shall give you another Comforter. So they were sitting, looking for the coming of the Holy Ghost; and when the day of Pentecost was fully come, here, in this city of Jerusalem,— (for this honour also belongs to us; and we speak not of the good things which have happened among others, but of those which have been vouchsafed among ourselves,)— on the day of Pentecost, I say, they were sitting, and the Comforter came down from heaven, the Guardian and Sanctifier of the Church, the Ruler of souls, the Pilot of the tempest-tossed, who leads the wanderers to the light, and presides over the combatants, and crowns the victors.
Source: Catechetical Lectures (New Advent)