Advent: "O Antiphons"

(This post has been updated. See below.)

A few months ago, my parish's bulletin began including a section called "Spiritual Food", which is a short couple of paragraphs on a particular liturgical or devotional topic. For instance, I've written about the role of the Blessed Virgin Mary (in our parish, our diocese, and our Catholic faith), the Feast of Corpus Christi, and St. Elizabeth Ann Seton. We're approaching Advent, and so the group of us who writes these tidbits were parceling out the next set of topics.

One listed was simply: "O Antiphons". I had no idea what that meant. I Googled it. Now I am enlightened:

The importance of “O Antiphons” is twofold: Each one highlights a title for the Messiah: O Sapientia (O Wisdom), O Adonai (O Lord), O Radix Jesse (O Root of Jesse), O Clavis David (O Key of David), O Oriens (O Rising Sun), O Rex Gentium (O King of the Nations), and O Emmanuel. Also, each one refers to the prophecy of Isaiah of the coming of the Messiah.

[Source: CatholicEducation.org]

The "O" Antiphons are the verses for the ancient hymn O Come, O Come Emmanuel. The first letter of the Messianic titles: Emmanuel, Rex, Oriens, Clavis, Radix, Adonai, Sapientia — spell out Latin words ERO CRAS, meaning, "Tomorrow, I will come."

The antiphons are part of the evening prayer of the Divine Office, the antiphon before and after the Magnificat. They are also the alleluia verse before the Gospel at Mass.

[Source: CatholicCulture.org]

Update: Here is a smattering of O Antiphon blog posts from other bloggers:

• O Antiphons of Advent (Dominican Friars)
  
• O Sapientia (New Liturgical Movement)
• O Antiphons (New Liturgical Movement)
• Dec 17 (Crossed the Tiber) (WDTPRS)
• Dec 18 (Crossed the Tiber) (WDTPRS)
• Dec 19 (Crossed the Tiber) (WDTPRS)
  
• Dec 20 (Crossed the Tiber) (WDTPRS)
• Dec 21 (Crossed the Tiber) (WDTPRS)
• Dec 22 (Crossed the Tiber) (WDTPRS)
• Dec 23 (Crossed the Tiber) (WDTPRS)