Isaiah 22:22: "I will place the key of the House of David on his shoulder. When he opens, no one shall shut; when he shuts, no one shall open. Revelation 3:7: "To the presiding spirit of the church in Philadelphia write this: 'The holy One, the true, who wields David's key, who opens and no one can close, who closes and no one can open'". Isaiah 42:6-7: "I formed you, and set you as a covenant of the people, a light for the nations, to open the eyes of the blind, to bring out prisoners from confinement, and from the dungeon those who live in darkness". The key and sceptre are traditional symbols of kingly power and authority. Christ, the anointed one, is the heir of David and possessor of the kingdom. Jesus himself also made use of this symbol, showing the prophetic relationship of the earthly kingdom of David to the kingdom of God. All power and authority was given to him after the resurrection, and he entrusted this power to "bind and to loose" to Peter and the ministers of his church.
In the closing petition we look to Jesus to unlock the fetters of sin that keep us tightly chained. It is he who frees us from our captivity. We recall the deliverance proclaimed by the psalmist of old: "they dwelt in darkness and gloom, bondsmen in want and in chains,...and he led them forth from darkness and gloom and broke their bonds asunder" (Psalm 107: 10, 14).
Reflections on this O Antiphon:
iBenedictines - O Clavis David
Blue Eyed Ennis - O Clavis David
Wellspring Reflections - O Key of David
Concordia Theology - O Clavis David
University of Notre Dame - He stands and knocks: The Key of David