O Day-spring, Brightness of the Light everlasting and Sun of righteousness:
come and enlighten him that sitteth in darkness and in the shadow of death.
Divine Worship: The Missal
‘The Church hails Christ as the Rising Sun at eventide on December 21st - the mid-winter solstice and darkest day of the year. It is the time of the night’s predominance, when the darkness seems to have overcome all. The sun is at its furthest remove from the northern hemisphere. It appears to pause as if in death - but only to return, rising once more to begin a new cycle in the seasons of life. The timing of the antiphon is perfect. It reflects the people's hope in the birth of a child destined to die that he might rise in a dawning that would conquer darkness forever. His appearance is a celebration of the true feast of Sol Invictus - the Unconquered Sun, whose brief pause in the tomb for three days would be followed by an eternal spring. So the unrestrained revelry of Christian Saturnalia is not, like its old pagan forerunner, some desperate antidote to the fears of winter. It is a sparkling elixir of joyful hope that, as Christ has triumphed over sin and death, so those he has redeemed will share his victory of every bleakness in the human condition that winter symbolises’.
from Seven Bells to Bethlehem: The O Antiphons by Fr Oliver Treanor
Fr Lee Kenyon