Here’s an excerpt from the correspondence with Professore Raffaele Giglio at the Department of Italian Literature, the University of Napoli Federico II last week, regarding the interpretation of the dream in Canto 9 in Purgatory (our translation):
The presence of the “Fire” and the motif of the kidnapping, even though in the dream, makes us able to anticipate that which was the aspiration of Dante; to reach the Divine, which in the Biblical Stories was represented in general as the burning bush, as vivid and living Fire.
Dante in his proceedings has had to confront and surpass many barriers of fire to continue his journey. The fire, in my interpretation, symbolizes the burning desire of the pilgrim towards that biblical image of the Divine. The fire is an expression of strong desire; and in the dream Dante has brought to completion that which burns inside of him: unifying himself with the Divine Fire. The image is symbolic, and could signify the aspiration towards this Fire-Divinity, which now in a dream seems to him to have happened.
Prof. Giglio’s course on Dante and Science is excellent, here:
Professor Raffaele Giglio, Dante Course