Commentary Purg IX 16-18

The greater truth, indeed the prophetic power, of dreams that came near morning was something of a commonplace in Dante's time.  See C.Inf.XXVI.7.  Beginning with Torraca (DDP Torraca.Purg.IX.16-18), twentieth-century commentators have reminded readers that in Convivio (Conv.II.viii.13) Dante adduced our awareness of our own immortality from the fact that our dreams foretold the future for us.