The Perilous Fountain with the Charter of Love

¶ Just as he lowered his head
And gazed upon his own face,
That great misfortune befell him
original: "mechief." This refers to a calamitous event or a tragic turn of luck, often used in medieval romance to describe the onset of unrequited or overwhelming love.
From which I believe he did not guard himself.
For then I saw an arm that burned,
Holding a dart—as I well remember—
Set ablaze with fire, and it was eager
To strike him through the middle of his body.

¶ With great force it brandished the dart,
Which had seen many a battle.
It struck the youth in that part
Of the body where the heart lies, without fail.
So much did it burn his heart and vital spirits,
original: "coraille." Literally the "coral" or the internal vital organs (like the liver and lungs). In medieval anatomy, these were the seat of the passions.
The blow harmed him greatly.
Then a voice spoke from within:
original: "encoraille." A poetic term suggesting the voice comes from the heart or is spoken with deep, inward sincerity.
"For from this blow, he shall never die."

¶ Soon the arm vanished,
And deigned to strike him no more.
Never again did I see it, nor did I hear
The voice that taught me these words.
But more than a hundred times, my heart
Crossed itself at what I saw then;
original: "se seigna." The narrator makes the sign of the cross in a gesture of religious shock or protection against the supernatural sight.
For the wound never bled,
original: "seigna." A play on words with the previous line; though the narrator crossed himself (se seigna), the wound itself did not bleed (ne seigna).
Nor was blood perceived from the outside.

¶ For a long time he lay thus on the ground,
Upon the bank of the fountain.