Is there a sin incurred by someone who was harmed by his paternal uncle’s wife’s gloating and malice, when he said: "Gloating is not part of my character, and I have never gloated over anyone, otherwise I would have gloated over her when my paternal uncle's wife did such-and-such to her daughter"; knowing that he did not mention the name of his paternal uncle's wife or her daughter, and the statement was in the third person, and his intention was to convey that gloating is not a sound moral trait?

What the questioner did by speaking ill of her uncle's wife is backbiting (Gheebah). Slander (Nameemah) differs from backbiting in that slander is intended to cause mischief. Ibn Hajar made a distinction between the two, indicating a general and specific relationship between them in one respect. Slander is the act of conveying someone's situation to another with the intention of causing mischief, whereas backbiting is speaking about someone in their absence in a way they would dislike. Slander and backbiting share commonalities in other aspects.

An exception to backbiting is speaking about an oppressor, provided that one does not exceed the bounds when talking about them in their absence. If her words contained insult towards her aunt's daughter, who did not wrong her, then it is backbiting if she was absent, and aggression and insult if she was present. It is incumbent to treat them with kindness.