"That the phrase actually originated in the Hispana is obvious for a simple reason: only in that collection do we find a textual corruption of the acts of the Council of Chalcedon at which one of the bishops modestly said that God imperatorem erexit ad zelum [i.e. fidei]. In other words, a scribe copying the canons of Chalcedon misread the text and changed ad zelum into ad celum; and this erroneous reading must have reached, perhaps through the channels of Pseudo-Isidorus, the Norman Anonymous for whom even that great forgery in favor of the hierarchy could turn into grist brought to his royalist mill. This reading is merely an error, though an error remarkable by itself, since it shows how easily any extravagant exaltation of the imperial power could flow from the pen of a scribe in those centuries."
January 1, 1970
https://en.wikiquote.org/wiki/Ernst_Kantorowicz