"The Moving Finger...

    ...writes; and, having writ,
    Moves on: nor all thy Piety nor Wit
    Shall lure it back to cancel half a Line,
    Nor all thy Tears wash out a Word of it."

"Some critics believe that FitzGerald's Omar is, in fact, an English poem with Persian allusions; FitzGerald interpolated, refined, and invented, but his Rubaiyat seems to demand that we read it as Persian and ancient.
The case invites speculations of a metaphysical nature. Omar professed (we know) the Platonic and Pythagorean doctrine of the souls passage through many bodies; centuries later, his own soul perhaps was reincarnated in England to fulfill, in a remote Germanic language streaked with Latin, the literary destiny that had been suppressed by mathematics in Nishapur. Isaac Luria the Lion taught that the soul of a dead man can enter an unfortunate soul to nourish or instruct it; perhaps, around 1857, Omar's soul took up residence in FitzGerald's. In the Rubaiyat we read that the history of the universe is a spectacle that God conceives, stages, and watches; that notion (whose technical name is pantheism) would allow us to believe that the Englishman could have recreated the Persian because both were, in essence, God or the momentary faces of God. More believable and no less marvelous than these speculations of a supernatural kind is the supposition of a benevolent coincidence. Clouds sometimes form the shapes of mountains or lions; similarly, the unhappiness of Edward FitzGerald and a manuscript of yellow paper and purple letters, forgotten on a shelf of the Bodleian at Oxford, formed, for our benefit, the poem.
All collaboration is mysterious. That of the Englishman and the Persian was even more so, for the two were quite different, and perhaps in life might not have been friends; death and vicissitudes and time led one to know the other and make them into a single poet."- Borges.