December 17 is the first day of the use of these ancient Magnificat antiphons. Each day through December 23, a different antiphon uses a mosaic of scriptural sources, the words of Old Testament prophets, to express the longing for the savior. Each begins with an invocation to the Messiah, continues with text that develops the messianic title, and closes with Come, an appeal for salvation and liberation that refers to the initial invocation. The seven-day format:
There are several Old Testament scriptural sources for the O Antiphons, easily found on the internet or in Advent worship aids. Some parishes may offer bible study groups that allow members to spend time with the wealth of these texts.
On Dec. 24 at Morning Prayer, when all the O Antiphons have been sung or prayed or studied, we pray in the Responsory:
Long had I been watching;
now I see God coming in power, as in a cloud of light.
The Messiah will come wrapped in splendor
as in a cloud of light.