The refrain in Latin is: "Rorate caeli desuper, et nubes pluant justum", which is translated as 'Drop down, ye heavens, from above, and let the clouds rain down the Just One.' There are four verses which are sung with this refrain and as the final verse is reminescent of yesterday's First Reading from Isaiah, I offer the last two verses in translation here:
"Behold, O Lord, the affliction of thy people and send forth Him who is to come:
Send forth the Lamb, the ruler of the earth,
From the rock of the desert, to the mount of the daughter of Sion:
That He may take away the yoke of our captivity.
Be comforted, be comforted, my people:
Thy salvation cometh quickly:
Why art thou consumed with grief?
For sorrow hath estranged thee: I will save thee;
Fear not, for I Am the Lord thy God,
The Holy One of Israel, thy Redeemer."
Come to deliver us, O Lord God of Hosts!
The painting above of the Annunciation is by El Greco (1541-1614).