The first line, “The banners of the king of Hell come forth,” is a parody of the first line of a Latin hymn of the sixth century, sung in the churches during Passion week, and written by Fortunatus, an Italian by birth, but who died Bishop of Poitiers in 600, The first stanza of this hymn is⁠—

“Vexilla regis prodeunt,

Fulget crucis mysterium,

Quo came carnis conditor,

Suspensus est patibulo.”

“Vexilla regis prodeunt, Fulget crucis mysterium, Quo came carnis conditor, Suspensus est patibulo.”