Drop down, ye heavens, from above, and let the skies pour forth righteousness..
Comfort ye, comfort ye my people, my salvation shall not tarry:
I have blotted out as a thick cloud thy transgressions:
fear not for I will save thee:
for I am the Lord thy god, the holy one of Israel, thy Redeemer.
Lazily searching for an online text that I could copy to save myself the trouble of typing it, I found it at a blog called Chantblog. I also found there this beautiful recording of the hymn in a chant setting. It's a bit puzzling to me, as it's the Book of Common Prayer English, but is described as Gregorian chant. Was it done fairly recently, or was chant used in Cranmer's time? I don't know and don't have time to dig into the question now.
The choir is the choir of St. Etheldreda's church, a Catholic church in London. I'll have to go back and read more about it. Did it stay Catholic through the Reformation?
Comfort ye, my people.