Yesterday Jansy asked: Perhaps the emergence of some such 666 Arabic algarisms in Nabokov might have been used by him as a hint for Crowley or at his theories about the Occult?
To quote the immortal Liza Doolittle, "not bloody likely!" I'm not sure what an algarism is (a spitting image perhaps?) but this is a direct reference to The Book of Revelations, to which Crowley also was alluding with his self-appointed nom de magique "The Beast". I was just listening yesterday to a negro spiritual about the author of that Book, "John the Revelator." Perhaps Shade is the anti-Revelator?