Genesis 4:23
And Lamech said unto his wives, Adah and Zillah, Hear my voice; ye wives of Lamech, hearken unto my speech: for I have slain a man to my wounding, and a young man to my hurt.
Cross-reference
Genesis 49:6
Contrast
In Genesis 49:6, Jacob condemns Simeon and Levi for killing men in anger—echoing the violence Lamech boasts about. One celebrates, the other condemns.