Genesis 4:23-24 New Revised Standard Version (NRSV)
23 Lamech said to his wives:
“Adah and Zillah, hear my voice;
you wives of Lamech, listen to what I say:
I have killed a man for wounding me,
a young man for striking me.
24 If Cain is avenged sevenfold,
truly Lamech seventy-sevenfold.”