Is a man's insulting his mother considered a form of slandering chaste women? What is the Hadd (prescribed punishment) for slandering chaste women? And will the Hadd be carried out in the Afterlife if it is not carried out in this world?

It is not permissible to insult another's mother unjustly, as it leads to insulting one's own mother, and this is among the gravest sins. If the insult includes an accusation of adultery (qadhf az-zina) or a denial of paternity, then the punishment for false accusation (hadd al-qadhf) is incurred, and slandering chaste women is among the major sins. The slanderer must offer sincere repentance and increase in righteous deeds.