O key of David - "O" Antiphons

O key of David and scepter of Israel, what you open no one else can close again; what you close no one can open. O come to lead the captive from prison; free those who sit in darkness and in the shadow of death.

    "I will place on his shoulder the key of the house of David; he shall open, and no one shall shut; he shall shut, and no one shall open." Isaiah 22:22

   "His authority shall grow continually, and there shall be endless peace for the throne of David and his kingdom. He will establish and uphold it with justice and with righteousness from this time onwards and for evermore." Isaiah 9:7

    "...To open the blind eyes, to bring out the prisoners from the prison, and them that sit in darkness out of the prison house." Isaiah 42:7.

King David - Wikimedia Commons
The Great O Antiphons of Advent | History and Meaning