As with all the ‘O’ antiphons O Clavis David (O Key of David) the Great Antiphon for 20 December is based upon the book of Isaiah, in this case Isaiah 22:22, Isaiah 9:7 ,and Isaiah 42:7:
Isaiah 22:22 Et dabo clavem domus David super humerum ejus; et aperiet, et non erit qui claudat; et claudet, et non erit qui aperiat. (And I will lay the key of the house of David upon his shoulder: and he shall open, and none shall shut: and he shall shut, and none shall open).
Isaiah 9:7 7 Multiplicabitur ejus imperium, et pacis non erit finis; super solium David, et super regnum ejus sedebit, ut confirmet illud et corroboret in judicio et justitia, amodo et usque in sempiternum : zelus Domini exercituum faciet hoc. (His empire shall be multiplied, and there shall be no end of peace: he shall sit upon the throne of David, and upon his kingdom; to establish it and strengthen it with judgment and with justice, from henceforth and for ever: the zeal of the Lord of hosts will perform this).
Isaiah 42:7 ut aperires oculos cæcorum, et educeres de conclusione vinctum, de domo carceris sedentes in tenebris. (That you might open the eyes of the blind, and bring forth the prisoner out of prison, and them that sit in darkness out of the prison house).
In Middle-Eastern cultures at the time keys were emblems of the Government’s authority during the coronation of a king or appointment of a provincial governor a large ornate key was laid up their shoulder to symbolise their taking up authority 1. Which is why Jesus is referred to as the the "Key of David" in this antiphon it’s a reference to his royal authority both as the son of the King of Heaven and as a descendant of King David. While the references to healing the blind, and opening of prisons are references to both physical and spiritual blindness and imprisonment. It’s sung below by Peter Morton (tenor) and the choir of St John’s College, Cambridge, conducted by David Hill. Enjoy :-).
- In fact the giving of a large ceremonial key is part of Christian religious ceremonies in the region to this day. ↩