Genesis 4:15

15 And the LORD said unto him, Therefore whosoever slayeth Cain, vengeance shall be taken on him sevenfold. And the LORD set a mark upon Cain, lest any finding him should kill him.
The King James Version is in the public domain.

Genesis 4:24

24 If Cain shall be avenged sevenfold, truly Lamech seventy and sevenfold.
The King James Version is in the public domain.