I have heard that the quote “The Devil is not as black as he is painted.” is due to Dante. Can someone please provide me a with a reference for this? I am guessing that it is somewhere in the Divine Comedy.
If the quote comes from Dante, its most likely origin would be the first part, Inferno, from the Divine Comedy. The Italian text of the Divine Comedy or Divina Commedia is available online (also in several editions on Archive.org).
che, per veder, non indugia 'l partire:
e vidi dietro a noi un diavol nero
correndo su per lo scoglio venire.
In Henry F. Cary's translation, the last two lines of this stanza are translated as follows:
Behind me I discern'd a devil black,
That running up advanced along the rock.
This is just a devil, not the devil.
Someone pointed out in a comment that a translation of "the Devil is not as black as he is painted" can be found in Franco Sacchetti's 14th-century work Il Trecentonovelle:
il diavolo non è nero come si dipigne
(See dipingere in the Italian Wiktionary.) Franco Sacchetti lived from c. 1335 – c. 1400 and lived in Florence in Tuscany (although it is not clear whether he was actually born there). This makes him a bit younger than Dante, who lived from c. 1265 – 1321.
However, Sacchetti's words may have been a variation on a Tuscan proverb, if that proverb already existed at the time:
Non bisogna fare il diavolo più nero di quanto non sia.
Meaning: there is no need to make (or "paint") the devil more black than he is.