A mention of the Nights in mystical form in the book The Sufis by Idries Shah (Anchor Books 1971) -
He begins his book with mentions of Sufi poetry as being secretive states of literary mysticism and says:
"In its most advanced form the secret language uses Semitic consonantal roots to conceal and reveal meanings; and Western scholars seem unaware that even the popular Thousand and One Nights is Sufic in content, and that its Arabic title Alf layla wa layla is a code phrase indicating its main content and intention: 'Mother of Records'" (x).
Idries Shah was a popular "mystical" new age writer who penned scores of books throughout the mid to end of the 20th century. His son Tahir Shah recently published his own book In Arabian Nights.