FitzGerald's translation is rhyming and metrical, and rather free. Many of the verses are paraphrased, and some of them cannot be confidently traced to his source material at all.[23] Michael Kearney claimed that FitzGerald described his work as "transmogrification".[24] To a large extent, the Rubaiyat can be considered original poetry by FitzGerald loosely based on Omar's quatrains rather than a "translation" in the narrow sense.
FitzGerald was open about the liberties he had taken with his source material:
My translation will interest you from its form, and also in many respects in its detail: very un-literal as it is. Many quatrains are mashed together: and something lost, I doubt, of Omar's simplicity, which is so much a virtue in him. (letter to E. B. Cowell, 9/3/58)
I suppose very few people have ever taken such Pains in Translation as I have: though certainly not to be literal. But at all Costs, a Thing must live: with a transfusion of one's own worse Life if one can't retain the Originals better. Better a live Sparrow than a stuffed Eagle. (letter to E. B. Cowell, 4/27/59)
For comparison, here are two versions of the same quatrain by FitzGerald, from the 1859 and 1889 editions:
Quatrain XI (1859) Herewith a Loaf of Bread beneath the Bough, A Flask of Wine, a Book of Verse—and Thou Beside me singing in the Wilderness— And Wilderness is Paradise enow.
Quatrain XII (1889)[25] A Book of Verses underneath the Bough, A Jug of Wine, a Loaf of Bread—and Thou Beside me singing in the Wilderness— Oh, Wilderness were Paradise enow!
This quatrain has a close correspondence in two of the quatrains in the Bodleian Library ms., numbers 149 and 155. In the literal prose translation of Edward Heron-Allen (1898):[26]
No. 149 I desire a little ruby wine and a book of verses, Just enough to keep me alive, and half a loaf is needful; And then, that I and thou should sit in a desolate place Is better than the kingdom of a sultan.
No. 155 If a loaf of wheaten-bread be forthcoming, a gourd of wine, and a thigh-bone of mutton, and then, if thou and I be sitting in the wilderness, — that would be a joy to which no sultan can set bounds.