Why Lamech, after the fifth generation, blames himself for the fratricide of his elder Cain; saying, as the scripture reports, to his wives, Adah and Zillah; "I have slain a man to my injury and a young man to my hurt; since if vengeance is taken upon Cain sevenfold, it shall certainly be taken on Lamech seventy and sevenfold?" (Genesis 4:23).