What is the ruling regarding the right to exact retribution (qadaf/hadd) when a man slanders (qadhafa) the deceased mother of two claimants, one waives the right to retribution and the other pursues it, and the pursuing claimant subsequently dies, leaving the waiving claimant as an heir?

Primary text

If a man slanders the deceased mother of two individuals (who possess the right to seek retribution/hadd for the slander), and one waives the right, while the other pursues the matter, and then the pursuing individual dies, leaving the waiving individual as heir, the right to exact the retribution is established for the heir. This is established based on the principle of acting by proxy (isti'fa bi al-niyaba) on behalf of the deceased brother, provided the legal opinion holds that the hadd (punishment) for slandering the deceased mother is obligatory.