The key of David. I.e. his flesh; not an unreal one, not an imaginary one as some heretics used to invent, but a true one as the Catholic Church confesses.
Or the key of David that opens the prophets is Christ, who revealed the hidden secrets of the Scriptures, and he is compared to a key because he opens to view that which is hidden and shut.
Or he shuts so that we may seek, he opens so that we may find, so that the seeker may receive the fruit of his sweat, and the bestower have the gratitude of his goodness. (Consolamini Commentary Series: The Glossa Ordinaria on Revelation: An English Translation [trans. Sarah Van Der Pas; West Monroe, La.: Consolamini Publications, 2015], 24)
