The great hymn, "O come, o come Emmanuel" is based on the Church's tradional prayer, the "O Antiphons". It is a series of daily prayers, right before Christmas, that focus us on different aspects of Christ. Today's is "O Wisdom":
O Wisdom, you came forth from the mouth of the Most High, and reaching from beginning to end, you ordered all things mightily and sweetly. Come, and teach us the way of prudence.