"Perfection belongs to Allah, 'tis impiety to achieve perfection".
I'm pretty sure I heard it in connection with the story of a deliberate defect in the columns of a Paris cathedral (not sure of the name, but the one with "Les mains a sept doigts") - I think one column in the vaults was left unfinished - and that in turn with the "apprentices column" - now is that in Ely Cathedral, or York, or a different one? - where the story was that the apprentice was making such a nice job that the master who was jealous of the skill of the apprentice that he murdered the apprentice before the apprentice could finish.....