Dies Irae and the Sibyls

“Dies irae, dies illa… teste David cum Sibylla.”
Day of wrath, that day, … as David witnessed with the Sibyl.
Wait … who exactly was this Sibyl? And why does she show up in the Requiem mass but not anywhere else in scripture or the liturgy? Early Music Monday continues with part 2 of Sacred or Secular this week!

The sibyls were oracles in Ancient Greece. The earliest sibyls, according to legend,[1] prophesied at holy sites. Their prophecies were influenced by divine inspiration from a deity; originally at Delphi and Pessinos. In Late Antiquity, various writers attested to the existence of sibyls in Greece, Italy, the Levant, and Asia Minor.

The English word sibyl (/ˈsɪbəl/ or /ˈsɪbɪl/) comes — via the Old French sibile and the Latin sibylla — from the ancient Greek Σίβυλλα (Sibulla).[2] Varro derived the name from theobule ("divine counsel"), but modern philologists mostly propose an Old Italic[3] or alternatively a Semitic etymology.[4]

The first known Greek writer to mention a sibyl is Heraclitus, in the 5th century BC:

The sibyls were oracles in Ancient Greece. The earliest sibyls, according to legend, prophesied at holy sites. Their prophecies were influenced by divine inspiration from a deity; originally at Delphi and Pessinos. In Late Antiquity, various writers attested to the existence of sibyls in Greece, Italy, the Levant, and Asia Minor.