This aspect of repetition is of course known to people who study this subject, but unknown to the general public. The layman seems to think, like I did, that the Koran is just another religious book similar to the Bible, the book of Mormon and such. The fact it is not, is known for a long time as you can see in the "to the reader" of this antique Koran, which belonged to the second president of the US John Adams.