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 18th December: O Adonai – O Lord
O Adonai, et Dux domus Israel, qui Moysi in igne flammae rubi apparuisti,
et ei in Sina legem dedisti:
veni ad redimendum nos in brachio extento.
Detail of a Levite City in Galilee mapped by the English cartographer Thomas Fuller, from A Pisgah Sight of Palestine, 1650 ISRAEL MUSEUM, IIAN STZULMAN O Adonai, and leader of the House of Israel,
who appeared to Moses in the fire of the burning bush
and gave him the law on Sinai:
Come and redeem us with an outstretched arm
Unsayable, you chose to speak one tongue,
Unseeable, you gave yourself away,
The Adonai, the Tetragramaton
Grew by a wayside in the light of day.
O you who dared to be a tribal God,
To own a language, people and a place,
Who chose to be exploited and betrayed,
If so you might be met with face to face,
Come to us here, who would not find you there,
Who chose to know the skin and not the pith,
Who heard no more than thunder in the air,
Who marked the mere events and not the myth.
Touch the bare branches of our unbelief
And blaze again like fire in every leaf.