L'Aurora intanto, candida e vermiglia,
Lieta apparìa nel lucido orizonte
E discoprìa l'antica maraviglia,
Come si faccia l'un da l'altro fonte:
Il primo, che 'l suo occulto e 'l ver somiglia,
Ha per sostegno un huom che pare un monte,
Lo qual gli homeri incurva, e quasi stanco
China al peso lucente il capo e 'l fianco.
Aurora meanwhile, white and vermilion,
Happily appeared on the shiny horizon
And showed that ancient marvel, namely
How these springs flow from one another:
The first one -- like truth and its secrets --
Is supported by a man as huge as a mount,
Who bends his shoulders and, almost tired,
Lowers his head under the sparkling weight.
Two mythological hints: the goddess Aurora (Dawn) and Atlas, who in this case supports the first spring, not the world. But the very parallel suggests that the spring symbolizes the universe, whose "tiredness" is powerfully expressed in the last lines of Tasso's Il Mondo Creato, that is basically the only passage in the poem reported in literary essays.
Line 5 is not clear at all. A more literal translation would read: "The first [spring], which recalls its hidden side and truth," where the former adjective "its" must probably be referred not to "spring" but to "truth" as a prolepsis. Maybe an echo from Dante, Paradiso 19: 42, that deals precisely with the creation of the world.