In the Eighth Century, beginning on December 17th the Church would sing a series of seven songs called the “O Antiphons” because they all began with “O”. Each of these songs are titled with a Messianic name from the Book of Isaiah.
Quoting Eric Mataxas:
“All of God’s promises to His people are fulfilled in the One whose coming we sing about.
“He is Sapienta, the Wisdom of God, upon whom the Spirit of wisdom and understanding, counsel and strength, and knowledge and fear of the Lord rested (Isaiah 11). He is Adonai, the Lord our lawgiver and judge, who will save us (Isaiah 33). He is the root of Jesse’s stem, whom the Gentiles will seek out and whose dwelling will be glorious (Isaiah 11). He is Oriens, the Radiant Dawn, the light that has shined upon the people who dwelt in darkness (Isaiah 9).
“He is all these things and so much more.
There is a pattern found in the Messianic titles of the seven songs. I think it is deliberate and an indication of the early Church looking forward to the Coming of the Lord Jesus. The first letter of each title, which are mostly in Latin, are as follows; S-A-R-C-O-R-E. If you reverse these letters, they say, “Ero Cras,” which is Latin for “Tomorrow I come.” I believe the early Church anxiously awaited the Coming.
“Even so, come Lord Jesus.” – Revelation 22:20
My thanks to Eric Metaxas for this fascinating information.
http://www.colsoncenter.org/about-us/about-eric-metaxas