Commentary Par XVII 1-6

Phaeton sought reassurance from his mother, Clymene, against the denial (on the part of his 'half-brother in divinity,' as it were, Epaphus, a son of Io by Jove) of his origin from divine Apollo's seed (see Metam. I.747-789 [setting up the lengthy narrative of Phaeton's disastrous chariot-ride in Metam. II.1-400]).  So now does Dante wish to be enlightened about the nature of the ills that will afflict him after 1300, ills that he has heard prophesied in Hell and in Purgatory (for all those prophetic passages [three of the last four are positive, not worrisome], see C.Par.XVII.43-99), even if he is assured of his eventual salvation.  Beatrice and Cacciaguida share the role of a wiser Apollo, confirming his purpose without destroying him by allowing a runaway journey through the heavens.  In Ovid's 'tragic' narrative Phaeton is, we remember, allowed to destroy himself through over-enthusiastic evaluation of his own capacities as rookie sun-driver; in Dante's comically resolved tale of his journey through the heavens, we see the protagonist as a wiser (and better-aided) version of Phaeton.

See Moore (Moor.1896.1), p. 175, comparing Cacciaguida's assurance that Dante will survive his troubles to the Sibyl's similar gesture toward Aeneas (Aen. VI.95-96); Moore goes on to mention both heroes' calm acceptance of their fates (cf. Aen. VI.103-105).  And see Schnapp (Schn.1991.2), pp. 217-19, and Picone (Pico.1994.1), pp. 181-82, for two particularly interesting responses to these verses.  Also see Brownlee (Brow.1984.1) for the 'Phaeton program' in the Commedia.

It is perhaps of interest that the male participants in this simile are identified only by periphrasis (Phaeton, Apollo, Cacciaguida) or (in the case of Dante) by a pronoun (io), while the female figures (Clymene, Beatrice) are named.