What does Genesis 5:29 mean?

This verse introduces the second major patriarch in the book of Genesis: Noah. Lamech's comments in this verse show a strong contrast between the lineage of Seth, and that of Cain. One of Cain's descendants was also named "Lamech," but he is recorded as bragging about his sin (Genesis 4:23–24). The Lamech described here, a descendant of Seth, is mourning the struggles humanity has faced since the fall. This results in him giving his son the name Noah, which sounds very much like the Hebrew word for "rest or comfort."

In addition, Lamech speaks a prophecy about his son: Out of the cursed ground, Noah would bring relief from the painful work and toil of his people's hands. Perhaps Lamech just meant that Noah would bring relief from God's curse on men by sharing in the painful work of getting crops from the ground. We don't know what Lamech had in mind. What God had in mind for Noah's lifetime, though, would bring a very specific kind of relief to the world in the form of a devastating flood that would wipe out the effects of so much human sin.