"Moreover, Dequin has found evidence that it was not until after the ʿAbbāsids had taken
over power that the pilgrimage to Mecca was established "
Funny that you would disagree on that and go to the point of thinking this is a total non sense.
"According to Dequin, both terms were originally gnostic concepts denoting redemptory figures, originally going back to Christological notions."
Well you should remember what you said a couple of months back when you read a commentary on the mahdi.