Cursing is unlawful. It is not befitting for a Muslim to curse, slander or be openly vulgar. It is recorded in an authentic hadeeth that the Prophet said,
“Cursing a Muslim is like killing him!” (Bukhaary 6105 and Muslim 110)
It is established that the Prophet ﷺ once heard a woman cursing her animal she uses to carry things on. He commanded her to leave it and let it roam freely. He said,
“Do not accompany us with an animal which has been cursed!” (Muslim 2595, 2596)
This proves that cursing is a major issue. Therefore, a Muslim should avoid it and not say it upon his tongue. We have mentioned evidence from the Scared Texts, the narration,
“Cursing a Muslim is like killing him!”
and killing a Muslim is evil, about which Allaah says,
(وَمَن يَقْتُلْ مُؤْمِنًۭا مُّتَعَمِّدًۭا فَجَزَآؤُهُۥ جَهَنَّمُ خَـٰلِدًۭا فِيهَا)
“Whoever kills a believer intentionally his reward will be the Fire and
he will reside therein forever.” (AN-Nisaa’ 93)
Hence, cursing has been made akin to killing. Killing a person has destroyed his chance on Earth, whereas cursing him destroys his chance in the Hereafter. The reason for this is that cursing a person means to want a person to be far from the Mercy of Allaah, Most High, therefore it is not permissible at all.