The 'O Antiphons' (an antiphon is a spoken response in a church service) have been used in liturgical Christian traditions since as far back as the sixth century. They are spoken before reading the Magnificat at Evening Prayer during the last seven days of Advent.
My thanks to Malcolm Guite for these poetic reflections. Here is the one for 19th December: O Radix Jesse – O Root of Jesse
O Radix Jesse, qui stas in signum populorum,
super quem continebunt reges os suum,
quem Gentes deprecabuntur:
veni ad liberandum nos, jam noli tardare.
Detail from the Tree of Jesse in the Lambeth Bible, c.1140-50
O Root of Jesse, standing
as a sign among the peoples;
before you kings will shut their mouths,
to you the nations will make their prayer:
Come and deliver us, and delay no longer
All of us sprung from one deep-hidden seed,We knew the virtues once of every weed,
Rose from a root invisible to all.
But, severed from the roots of ritual,
We surf the surface of a wide-screen world
And find no virtue in the virtual.
We shrivel on the edges of a wood
Whose heart we once inhabited in love,
Now we have need of you, forgotten Root,
The stock and stem of every living thing
Whom once we worshiped in the sacred grove,
For now is winter, now is withering
Unless we let you root us deep within,
Under the ground of being, graft us in.