The proverbial expression of the mills of God grinding slowly refers to the notion of slow but certain divine retribution. Plutarch (1st century AD) alludes to the metaphor as a then-current adage in his Moralia (De sera numinis vindicta "On the Delay of Divine Vengeance"): "Thus, I do not see what use there is in those mills of the gods said to grind so late as to render punishment hard to be recognized, and to make wickedness fearless." Ὀψὲ θεῶν ἀλέουσι μύλοι, ἀλέουσι δὲ λεπτά. "The millstones of the gods grind late, but they grind fine."