A sign, saying or image that anticipates, sometimes only for those who reread, something that will happen later in the work.
In Purgatory
as far as reason sees here, I can tell you; from there on, wait only for Beatrice, for it is a work of faith.
Virgil says that from there on one must wait "only for Beatrice." The sentence foreshadows the woman who will take Virgil's place, and the reader sees her arrive, in the last cantos, just when Virgil disappears.
Cantos XVII to XXI: Love, sloth and avarice, Virgil, to Dante, marking the limit of reason