Day of wrath and doom impending. David's word with Sibyl's blending, Heaven and earth in ashes ending. We open with the Dies Irae, because it applies to the Three Days of Darkness. Pope Saint Gregory the Great says in his Regula Pastoralis: "Let them be told how the Prophet Sophonias holds out over them the stroke of divine reproof, when he says: 'Behold, the day of the Lord is coming, great and horrible . . . . That day is a day of wrath, a day of...