v. 1. The youth.] Phaeton, who came to his mother Clymene, to inquire of her if he were indeed the son of Apollo. See Ovid, Met. 1. i. ad finem.

v. 6. That saintly lamp.] Cacciaguida.

v. 12. To own thy thirst.] “That thou mayst obtain from others a solution of any doubt that may occur to thee.”

v. 15. Thou seest as clear.] “Thou beholdest future events, with the same clearness of evidence, that we discern the simplest mathematical demonstrations.”

v. 19. The point.] The divine nature.

v. 27. The arrow.] Nam praevisa minus laedere tela solent. Ovid.

Che piaga antiveduta assai men duole.
Petrarca, Trionfo del Tempo

v. 38. Contingency.] “The evidence with which we see the future portrayed in the source of all truth, no more necessitates that future than does the image, reflected in the sight by a ship sailing down a stream, necessitate the motion of the vessel.”

v. 43. From thence.] “From the eternal sight; the view of the Deity.

v. 49. There.] At Rome, where the expulsion of Dante’s party from Florence was then plotting, in 1300.