The lowest stair was marble white so smooth
And polish’d, that therein my mirror’d form
Distinct I saw.  The next of hue more dark
Than sablest grain, a rough and singed block,
Crack’d lengthwise and across.  The third, that lay
Massy above, seem’d porphyry, that flam’d
Red as the life-blood spouting from a vein. 
On this God’s angel either foot sustain’d,
Upon the threshold seated, which appear’d
A rock of diamond.  Up the trinal steps
My leader cheerily drew me.  “Ask,” said he,

“With humble heart, that he unbar the bolt.”

Piously at his holy feet devolv’d
I cast me, praying him for pity’s sake
That he would open to me:  but first fell
Thrice on my bosom prostrate.  Seven times
The letter, that denotes the inward stain,
He on my forehead with the blunted point
Of his drawn sword inscrib’d.  And “Look,” he cried,
“When enter’d, that thou wash these scars away.”

Ashes, or earth ta’en dry out of the ground,
Were of one colour with the robe he wore. 
From underneath that vestment forth he drew
Two keys of metal twain:  the one was gold,
Its fellow silver.  With the pallid first,
And next the burnish’d, he so ply’d the gate,
As to content me well.  “Whenever one
Faileth of these, that in the keyhole straight
It turn not, to this alley then expect
Access in vain.”  Such were the words he spake. 
“One is more precious:  but the other needs
Skill and sagacity, large share of each,
Ere its good task to disengage the knot
Be worthily perform’d.  From Peter these
I hold, of him instructed, that I err
Rather in opening than in keeping fast;
So but the suppliant at my feet implore.”

Then of that hallow’d gate he thrust the door,
Exclaiming, “Enter, but this warning hear: 
He forth again departs who looks behind.”

As in the hinges of that sacred ward
The swivels turn’d, sonorous metal strong,
Harsh was the grating; nor so surlily
Roar’d the Tarpeian, when by force bereft
Of good Metellus, thenceforth from his loss
To leanness doom’d.  Attentively I turn’d,
List’ning the thunder, that first issued forth;
And “We praise thee, O God,” methought I heard
In accents blended with sweet melody. 
The strains came o’er mine ear, e’en as the sound
Of choral voices, that in solemn chant
With organ mingle, and, now high and clear,
Come swelling, now float indistinct away.

CANTO X

When we had passed the threshold of the gate
(Which the soul’s ill affection doth disuse,
Making the crooked seem the straighter path),
I heard its closing sound.  Had mine eyes turn’d,
For that offence what plea might have avail’d?

We mounted up the riven rock, that wound
On either side alternate, as the wave
Flies and advances.  “Here some little art
Behooves us,” said my leader, “that our steps
Observe the varying flexure of the path.”