Prohibition of Cursing one Particular Man or Animal
Abud-Darda' (May Allah be pleased with him) said: The Messenger of Allah صلى الله عليه وسلم said, "When a person curses somebody or something, the curse goes up to heaven and the gates of heaven get closed. Then it comes down to the earth and its gates get closed. Then it turns right and left, and if it does not find an entrance to go anywhere, it returns to the person or thing that was cursed; if he or it deserves to be cursed; otherwise it returns to the person who uttered it.''
[Abu Dawud].
Commentary: Al-La'nah (curse) means deprivation of Allah's Mercy. We learn from this Hadith that the act of cursing is such that one who does it can become himself a victim of it. One should, therefore, abstain from cursing.