AsalamuAlaykum Warahmatullahi Wabarakatuh,
Sahih Al-Bukhari Vol. 8 No. 73 Narrated by Thabit bin Ad Dahhak (raa): Allah's Messenger (saws) said, "Whoever swears by a religion other than Islam (i.e. if somebody swears by saying that he is a non-Muslim e.g., a Jew or a Christian, etc.) in case he is telling a lie, he is really so if his oath is false, and a person is not bound to fulfill a vow about a thing which he does not possess. And if somebody commits suicide with anything in this world, he will be tortured with that very thing on the Day of Resurrection. And if somebody curses a believer, then his sin will be as if he murdered him. And whoever accuses a believer of Kufr (disbelief), then it is as if he killed him."
Our beloved Prophet, Allah bless him and give him peace, said, "The believer is not one who slanders, curses or uses vulgarity
(Tirmidhi, hadith hasan).
Abu Zaid Thabit bin Ad-Dahhak Al-Ansari (May Allah be pleased with him( (he is one of those who gave their pledge of allegiance to the Messenger of Allah (PBUH) under the Tree) said: The Messenger of Allah (PBUH) said, "He who swears by a religion other than that of Islam, is like what he has professed. He who kills himself with something, will be tormented with it on the Day of Resurrection. A person is not bound to fulfill a vow about something which he does not possess. Cursing a believer is like murdering him.''
[Al-Bukhari and Muslim].
"He who swears by a religion other than that of Islam'' here means either of the two things stated here. For instance, if a person says: "If I do such and such, then I am a Christian or a Jew.'' Now if he really intends to embrace Christianity or Judaism, he will immediately become so because his intention to be a Kafir (disbeliever) is Kufr (infidelity) in itself. But if the vow is meant to deny the adoption of other religions and is intended to express his firm resolution to live as a Muslim to the last even then such a vow is undesirable and is a sin for which one must seek Allah's forgiveness. The last sentence of this Hadith evidently shows that to curse a Muslim is forbidden because it is akin to killing him.
Abu Hurairah (May Allah be pleased with him) said: The Messenger of Allah (PBUH) said: "It does not befit a Siddiq (righteous Muslim) to frequently curse others.''
Taunts, curses and abusive language are contrary to perfect Faith and fidelity.
Abud-Darda' (May Allah be pleased with him) said: The Messenger of Allah (PBUH) said, "Those who frequently resort to cursing (people) would neither be accepted as witnesses nor as intercessors on the Day of Resurrection.''
The habit of taunting and cursing makes a man sinful. Such a person has no value with Allah, and his testimony and intercession will not be considered on the Day of Judgement.
Samurah bin Jundub (May Allah be pleased with him) said: The Messenger of Allah (PBUH) said, "Do not curse one another, invoking Curse of Allah or Wrath of Allah or the fire of Hell.''
[Abu Dawud and At-Tirmidhi].
We learn from this Hadith that Muslims should neither curse nor imprecate each other. For instance they are forbidden to say "May the Curse of Allah be upon you'' or "I wish you to burn in Hell-fire'' etc., etc.
Ibn Mas`ud (May Allah be pleased with him) reported: The Messenger of Allah (PBUH) said, "A true believer is not involved in taunting, or frequently cursing (others) or in indecency or abusing.''
This Hadith tells us the virtues of a Mu'min (true Muslim). Taunting here means to disgrace someone with reference to his lineage or by means of backbiting and slander. La`in is a person who is given to frequently cursing others, reproaching and using abusive language. (Fahish) is one who commits through word or practice immodesty. Badhiy is a person with a loose tongue. This word is also used for an impudent and abusive person. This Hadith strongly criticizes these vices.
Abud-Darda' (May Allah be pleased with him) said: The Messenger of Allah (PBUH) 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.''
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.
`Imran bin Husain (May Allah be pleased with him) said: We were with the Messenger of Allah (PBUH) on a journey and there was a woman from the Ansar riding a she-camel. She abused and invoked curse upon it. The Messenger of Allah (PBUH) heard it and said, "Off load the she-camel and set it free because it has been cursed.''
This Hadith teaches us not to curse animals. It also teaches us to treat them nicely and be patient with them..
WalaykumSalaam Warahmatullahi Wabarakatuh.