EDGAR ALLAN POE copiously annotated ‘Al Aaraaf’, his 1829 long poem, to give it an aura of erudition. In so doing, he deliberately obfuscated his sources, and several have yet to be identified. Consider his reference to moonblindness. At one point, the poem mentions a wildflower ‘That keeps, from the dreamer, / The moonbeam away’. Poe's annotation to these lines reads as follows: ‘In Scripture is this passage—“The sun shall not harm thee by day, nor the moon by night” (lines 70–71). It is perhaps not generally known that the moon, in Egypt, has the effect of producing blindness to those who sleep with the face exposed to its rays, to which circumstance the passage evidently alludes.’1 Thomas Mabbott, who indefatigably traced many of Poe's allusions to their sources, threw up his hands at this one, admitting, ‘Poe's source for the moon blindness of Egypt has not yet been found.’2 Poe's source was John Carne's Letters from the East: Written During a Recent Tour through Turkey, Egypt, Arabia, the Holy Land, Syria, and Greece, first published just three years before Poe published Al Aaraaf, Tamerlane, and Minor Poems. Carne quotes the identical passage of scripture (Psalms 121:6) and describes moon blindness in detail. Relating his experience sailing down the Nile at night, Carne explains: Our progress was rather slow, as the crew appeared indifferent sailors; but nothing could be more lovely than to glide along at night in the calm cloudless moonlight: amidst such scenery it was difficult to close one's eyes in sleep. The effect of the moonlight on the eyes in this country is singularly injurious: the natives tell you, as I found afterwards they also did in Arabia, always to cover your eyes when you sleep in the open air. It is rather strange that passage in the Psalms, ‘the sun shall not strike thee by day, nor the moon by night,’ should not have been thus illustrated, as the allusion seems direct. The moon here really strikes and affects the sight, when you sleep exposed to it, much more than the sun: a fact, of which I had a very unpleasant proof one night, and took care to guard against it afterwards: indeed the sight of a person who should sleep with his face exposed at night, would soon be utterly impaired or destroyed.3