(The texts of these antiphons are the basis for the popular Advent hymn, “O Come, O Come Emmanuel." For those of you who really want to be “inside baseball” on this topic, Jeffrey Tucker wrote a brilliant article on the history of the tune over at the New Liturgical Movement, here.)
Several years ago in a discussion thread at the Musica Sacra forum, a member pointed out that the text of the “O” antiphons is actually a very clever word game. The seven invocations in the original Latin are: Sapientia, Adonai, Radix Jesse, Clavis David, Oriens, Rex gentium and Emmanuel. The first letter of each spell S-A-R-C-O-R-E, which when reversed spells “Ero cras”, which in turn translated from Latin means “tomorrow I shall be.” An appropriate expression for Christmas Eve, the day after the "O Antiphons" end.
As the member said, “Very clever, those medievals.”
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