From Paradise Lost Book 3

Hail, holy Light, offspring of Heaven firstborn,
Or of the Eternal coeternal beam
May I express thee unblam'd? since God is light,
And never but in unapproached light
Dwelt from eternity, dwelt then in thee
Bright effluence of bright essence increate.
Or hear"st thou rather pure ethereal stream,
Whose fountain who shall tell? before the sun,
Before the Heavens thou wert, and at the voice
Of God, as with a mantle, didst invest
The rising world of waters dark and deep,
Won from the void and formless infinite.
Thee I re-visit now with bolder wing,
Escap'd the Stygian pool, though long detain'd
In that obscure sojourn, while in my flight
Through utter and through middle darkness borne,
With other notes than to the Orphean lyre
I sung of Chaos and eternal Night;
Taught by the heavenly Muse to venture down
The dark descent, and up to re-ascend,
Though hard and rare: Thee I revisit safe,
And feel thy sovran vital lamp; but thou
Revisit'st not these eyes, that roll in vain
To find thy piercing ray, and find no dawn;
So thick a drop serene hath quench'd their orbs,
Or dim suffusion veil'd. Yet not the more
Cease I to wander, where the Muses haunt,
Clear spring, or shady grove, or sunny hill,
Smit with the love of sacred song; but chief
Thee, Sion, and the flowery brooks beneath,
That wash thy hallow'd feet, and warbling flow,
Nightly I visit: nor sometimes forget
So were I equall'd with them in renown,
Thy sovran command, that Man should find grace;
Blind Thamyris, and blind Maeonides,
And Tiresias, and Phineus, prophets old:
Then feed on thoughts, that voluntary move
Harmonious numbers; as the wakeful bird
Sings darkling, and in shadiest covert hid
Tunes her nocturnal note. Thus with the year
Seasons return; but not to me returns
Day, or the sweet approach of even or morn,
Or sight of vernal bloom, or summer's rose,
Or flocks, or herds, or human face divine;
But cloud instead, and ever-during dark
Surrounds me, from the cheerful ways of men
Cut off, and for the book of knowledge fair
Presented with a universal blank
Of nature's works to me expung'd and ras'd,
And wisdom at one entrance quite shut out.
So much the rather thou, celestial Light,
Shine inward, and the mind through all her powers
Irradiate; there plant eyes, all mist from thence
Purge and disperse, that I may see and tell
Of things invisible to mortal sight.

--John Milton