Homer, The Iliad. Trans. E. V. Rieu (London: Penguin Books, 1950), IX.500-510:
Do you not know that prayers are Daughters of Almighty Zeus? They are wrinkled creatures, with a halting gait and downcast eyes, who make it their business to follow Sin about. But Sin is strong, and quick enough to leave them all behind. Stealing a march on them, she roams the world and brings mankind to grief. They come after and put the trouble right. The man who receives these Daughters of Zeus with humility when they approach him, is greatly blessed by them and has his own petitions granted. But when a man hardens his heart and rebuffs them, they go and pray to Zeus the son of Cronos that he may himself be overtaken by Sin and punished through his fall.