Genesis 4:19-24 "Lamech took two wives; the name of the one was Adah ...

Passage: 

"Lamech took two wives; the name of the one was Adah, and the name of the other Zillah. Adah bore Jabal; he was the ancestor of those who live in tents and have livestock. His brother's name was Jubal; he was the ancestor of all those who play the lyre and pipe. Zillah bore Tubal-cain, who made all kinds of bronze and iron tools. The sister of Tubal-cain was Naamah. 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. If Cain is avenged sevenfold, truly Lamech seventy-sevenfold.'"

Comment: 

Lamech is the sixth generation of descendents of Adam and Eve. His only purpose in the unfolding story would seem to be as an indication that human life is becoming increasingly advanced and specialized, as his sons become shepherds, musicians and smiths. Verses 23 and 24 are apparently from an ancient song, included to indicate that evil is also increasing in the world. Cain slew one man (albeit his brother) while Lamech, Cain's descendent, slew two. Having made this point, the storyteller shifts focus from Cain and his descendents to Seth and his.