The Odyssey 1.32–43

Even as now Aegisthus, beyond that which was ordained, took to himself the wedded wife of the son of Atreus, and slew him on his return, though well he knew of sheer destruction, seeing that we spake to him before, sending Hermes, the keen-sighted Argeiphontes,1 that he should neither slay the man nor woo his wife; for from Orestes shall come vengeance for the son of Atreus when once he has come to manhood and longs for his own land. So Hermes spoke, but for all his good intent he prevailed not upon the heart of Aegisthus; and now he has paid the full price of all.”