Cain's poison flowers seven generations down, and the horror is that it now sings. Lamech gathers an audience, commands his wives to listen, and turns a killing into a boast. Cain at least hid; his descendant advertises. That is the trajectory of unaddressed resentment passed along a bloodline and never confronted. It runs from a hidden crime to a proud one, from murder committed in shame to murder recited as anthem.
What began as one man's grievance against his brother has become a family that measures itself by its capacity to wound. Resentment that is nursed rather than examined does not stay contained in the individual. It compounds across generations, escalating from personal vengeance toward organized slaughter, until whole peoples are armed by an old private bitterness nobody ever set right. The wound one man refuses to heal becomes the war his grandchildren inherit.