Beatrice and the seven virtues sing a lament — Deus, venerunt gentes, Psalm 79, the lamentation over Jerusalem's ruin applied to the Church's desolation. Beatrice then speaks directly to Dante: she gives a prophecy, deliberately obscure even to Dante himself. A DXV — a 515 — will come, sent by God, to slay the whore and the giant. The number in Roman numerals, rearranged, gives DVX — a leader, a dux. Many interpreters have understood this as Dante's hope for a political deliverer, perhaps an emperor, who will restore order to the Church and Empire. But Beatrice says plainly: don't worry about not understanding it now; just remember it, and report it when you return to living men, even if they cannot understand it. The prophecy is a sealed message for the future.
Beatrice rebukes Dante gently for his continued confusion: his mind has been hardened by stony attachments; even her light cannot fully penetrate yet. She tells him she speaks in this obscure style because he must learn to lift his thought to her level, not bring her thought down to his. The difficulty of understanding is itself diagnostic — it reveals how far Dante still has to go, even at the summit of Purgatory.
They walk together to the Eunoe. Matelda draws Dante in — as she had drawn him through Lethe — and he drinks of the sweet, life-restoring water that brings back the memory of every good he has done. The experience cannot be expressed; Dante says he is like a plant renewed in new leaves, pure and ready. And with that word — puro, pure — the canticle ends: "pure and ready to mount to the stars." The last word of the Purgatorio, as of the Inferno before it, is stelle — stars. Dante's eyes are always upward. The darkness of the Inferno gave way to the dawn of Purgatory's shore; now Purgatory itself gives way to Heaven. The journey is not done. But Dante is finally, fully ready.