Commentary Inf XX 127-129

Once again (see, for example, [Inf XVI 106-108]) Dante adds a detail to an earlier scene in the poem, the prologue, the action of which takes place on this earth. There is no mention of the moon in the first Canto. It is also not possible that Virgil means yesterday night, as some propose, for Dante and Virgil were then already in hell, having begun their descent on Friday evening after Dante spent his night in the wood on Thursday: '"yesternight," i.e. the night before last, it being now early morning' is the explanation offered in Tozer's gloss on this verse (DDP Tozer.Inf.XX.127).