- Today we have finally reached the Fourth Sunday of Advent. During the tail-end of this season, from Dec 17 to 23, the Church observes the ancient custom of praying on each day one of the seven “O” Antiphons. They are called “O” Antiphons because each one addresses the Son of God with a different Old Testament title, beginning with the invocation “O”. These texts, traced back to seventh-century Europe, are drenched in biblical allusions offering a rich source for personal prayer and reflection during these final days of preparation for the celebration of Christmas. They also appear in the liturgy as the Gospel acclamations for each day and there is a verse for each one in the famous hymn “O Come, O Come, Emmanuel”. So, for example, up until today we have prayed to God the Son “O Wisdom”, “O Root of Jesse”, and “O Key of David”. After today we will pray to Him “O King of Nations” and finally “O Emmanuel.” But today, we pray to Him “O Dayspring”.