Rorate Caeli (Introit)

The Fourth Sunday of Advent recalls the Annunciation when the Word of God took flesh in the womb of the Virgin Mary. As such, we find that the entrance chant (Introit) for both this final Sunday of Advent and the feast of the Annunciation (25 March) are the same. The words are taken from Isaiah 45:8 but given a specifically Christ-centred interpretation: "Shower, O heavens, from above, and let the skies rain down the Just One; let the earth open, that the Saviour may sprout forth, and let it cause justice to spring up also; I the LORD have begotten him."

Below is a video of this chant sung by the Dominican brothers at Blackfriars Oxford. As is typical of an entrance chant, the 'Gloria Patri' is sung after the verse from Isaiah, and then the refrain is repeated.