The O Antiphon for December 20 is O Key of David (O Clavis David). This title hearkens to Isaiah 22:22, in which God promises to give the Key of David to His servant, who will have the power to open and shut the kingdom of David. Although this prophecy was about someone else when Isaiah gave it, it finds its ultimate fulfillment in Christ, who alone has authority to open Heaven. Jesus shares this authority today with the successors of His apostles, who have the power to release people from the captivity of sin through the Sacrament of Reconciliation.
Learn more about the O Antiphons: http://www.simplycatholic.com/what-are-the-o-antiphons/
