This phrase means the results of the guilt will happen to Joab and his family as if something heavy had collapsed on them. Alternate translation: "always cause suffering for Joab and for all his father's house" (See: [[rc://en/ta/man/translate/figs-metaphor]])
This double negative emphasizes that there will always be someone with the problems listed. Alternate translation: "May there always be" (See: [[rc://en/ta/man/translate/figs-metonymy]])