Backbiting means to say bad things about a person when he/she is not present. It is a very bad habit which Allah has strongly condemned in the Quran.
Allah says: O you who believe! Avoid suspicion as much (as possible), for suspicion in some cases is a sin: and spy not on each other, nor speak ill of each other behind their backs. Would any of you like to eat the flesh of his dead brother? Nay, would you abhor it. But fear Allah, for Allah is Oft-Returning, Most-Merciful.
In this verse Allah stresses his disgust with backbiting by comparing it to eating the flesh of one’s dead brother.
We should not backbite, and if we hear others backbiting, we should not join them. We should either correct them, turn the conversation to another topic, or just leave. If that is not possible, we should at least be silent.
Allah has forbidden backbiting, because it can be very hurtful and ruin a person’s reputation. When talking about other people, we should try to thnk: would I be able to say these things about this person to his face? If not, we should not be discussing such matters in their absence, because they don’t have the chance to clarify or defend their actions.
Cursing is a form of verbal abuse using vulgar language or to wish misfortune on a person. A curse can be sometimes conveyed by gestures of the hands. Cursing is disrespectful and indecent. Rasulullah (PBUH) repeatedly warned against cursing:
Do not use bad lagnuage, for Allah does not like bad language or the use of it.
(Transmitted by Bukhari and Aby Da’wud)
The believer does not taunt, curse, abuse anyone, or talk indecently.
(Transmitted by tirmidhi)
The sin of verbally abusing people is so great that all the rewards one has earned form prayer, fasting, Hajj, and other religous duties will not erase it. Such a person is deprived of Allah’s mercy.
A person who is rude and has a harsh tongue will not be admitted to Jannah (paradise).
Rasulullah (PBUH) also warned that those who wish evil on others:
Whoever curses a thing when it does not deserve it causes the curse to return upon himself.
(Transmitted by Tirmidhi and Abu Da’wud)
Therefore, we should learn to control our anger and our tongues, so that we do not harm others or harm ourselves.
This information was taken from the book, Islamic Tahdhib and Akhlaq-Theory and Practice by B. Aisha Lemu.