From December 17-23 the Church observes the ancient custom of praying each day one of the seven
O Antiphons (each begins with "O")
Each addresses God
who comes in Christ
with a different biblical title.
The seven in Latin are given above but here they are in English
O Root of Jesse
O Key of David
O King of Nations
These are found in the Liturgy each day and today we have
O Dayspring, brightness of eternal Light and Son of Justice:
come and enlighten those who sit in darkness and in the shadow of death.