What is the ruling on someone who slanders another with an implicit phrase such as "son of a whore," or with an explicit phrase such as "son of adultery," without intending to accuse of slander or that his mother is an adulteress? And is someone who curses the religion, not intending it, by saying "may your religion be cursed," considered an infidel?

A Muslim must guard his tongue. The saying of one who says, "Son of a whore," is among the metaphorical expressions, unless it is used in the custom of the land to accuse of adultery, in which case it becomes an explicit accusation that necessitates the ḥadd punishment. As for explicit terms like "adultery" or "son of adultery," they necessitate the ḥadd punishment and do not admit of interpretation. The ḥadd punishment for slandering chastity is a right of the slandered person, and insulting religion is an act of disbelief that expels one from the fold of Islam.