Bk XIV:101-153 Aeneas and the Sybil of Cumae.
When he had passed those islands, and left the walls of Parthenope behind him to starboard, the tomb of Misenus, the trumpeter, the son of Aeolus, was to larboard, and the shore of Cumae, a place filled with marshy sedges. He entered the cave of the Sibyl, and asked to go down to Avernus, to find his father's ghost. Then the Sibyl after remaining, for a long time, with her eyes gazing at the earth, lifted them, at last, filled with the frenzy of the god, and cried: "You ask great things, man of great achievements, whose hand has been tested by the sword, whose faith has been tested by the fire. But have no fear, Trojan, you will have what you desire, and, with me as your guide, you will know the halls of Elysium, and earth's strangest realm, and the likeness of your dear father. To virtue, no way is barred."
She spoke, and pointed out to him a gleaming golden bough, in the woods of Proserpine, the Juno of Avernus, and ordered him to break it from the tree. Aeneas obeyed, and saw the power of dread Dis, and he saw his own ancestors, and the ancient shade of great-souled Anchises. He learned also the laws of those regions, and the trials he must undergo in fresh wars.
Then taking the return path, with weary paces, he eased the labour by talking with his Cumean guide. As he travelled the fearful road through the shadowy twilight, he said: "Whether you are truly a goddess, or only most beloved by the gods, you will always be like a goddess to me, and I will acknowledge myself in your debt, who have allowed me to enter the place of the dead, and having seen that place of the dead, escape it. When I reach the upper air, I will build a temple to you, for this service, and burn incense in your honour."
The priestess gazed at him and with a deep sigh, said: "I am not a goddess: and do not assume any human being is worth the honour of holy incense, or err out of ignorance. I was offered eternal life without end, if I would surrender my virginity to Phoebus my lover. While he still hoped for it, while he desired to bribe me beforehand with gifts, he said: 'Virgin of Cumae, choose what you wish, and what you wish you shall have.' Pointing to a pile of dust, that had collected, I foolishly begged to have as many anniversaries of my birth, as were represented by the dust. But I forgot to ask that the years should be accompanied by youth. He gave me the years, and lasting youth, as well, if I would surrender: I rejected Phoebus's gift, and never married.
But now my more fruitful time has turned its back on me, and old age comes, with tottering step, that must be long endured. Though I have now lived seven centuries, three hundred harvests, three hundred vintages, still remain to be seen, to equal the content of the dust. The time will come when the passage of days will render such body as I have tiny, and my limbs, consumed with age, will reduce to the slightest of burdens. I will be thought never to have loved, and never to have delighted a god. Phoebus too perhaps will either not know me, or will deny that he loved me. I will go as far as having to suffer transformation, and I will be viewed as non-existent, but still known as a voice: the fates will bequeath me a voice."