Composed in 3s to correspond to the Trinity (Father, Son, Holy Ghost):

Inferno: 1 introductory canto, 33 cantos

Purgatorio: 33 cantos

Paradiso: 33 cantos

Total: 100 (the square of 10 regarded as the perfect number)

Dante's journey takes 3 days, from Good Friday to Easter Sunday

He says the journey takes place in 1300 when he was 35 (the middle of his life span: "Nel mezzo cammin di nostra vita")

Entire Commedia composed in Terza Rima (3-line stanza with interlocking rhyme scheme)

Nel mezzo del commin di nostra vita

mi retrovai per una selva oscura

che la diritta via era smarrita.

Ah, quanto a dir qual era e cosa dura

esta selva selvaggia e aspra e forte

che nel pensier rinova la paura!

Inferno arranged in 3 different levels with 9 circles:

Sins of Incontinence (Circles 2-5)

Sins of Violence (Circle 7)

Sins of Fraud (Circle 8 and 9)

Multiples of 3: 3X3=9

9 circles of Inferno; 9 of Purgatorio; 9 of Paradiso+1, Empyrean,= 10 (perfect number)