Translation of Genesis 4:23
Lamech said to his wives Adah and Zillah: Hear my voice, wives of Lamech, hear my saying, because I have killed a man as my wound and a child by my hit.
Translation of Genesis 4:24
As for avenge of Cain is sevenfold, for Lamech it's 77 times.
"My wound and... my hit" can be understood either as that Lamech killed two people by the wounds he have caused to them, or as psychological trauma of the killer (Lamech) himself.
Why the avenge of Lamech is greater than for Cain?
One preacher says: Cain was ashamed of his sin an afraid of a punishment, but Lamech was not ashamed but reversely proudly made a poesy about his killing and proudly assumed that the punishment for the revenge would be not 7 but 77 times.
Analyzing of information presented on this page is complete (even with spaces hypothesis). That is, all variants of translation were considered carefully. No warranty however, that nothing is missing.