Islam prohibits backbiting and slandering
And the worst of all sins are those that are greatest in harm and danger to humanity. Among the destructive major sins are backbiting and slandering. These two sins are forbidden by Allah (swt) because they sow enmity, evils and discord among people and lead to destruction. They cause hostilities between people of the same household and between neighbors and relatives. They can decrease in good deeds and increase in evil ones and lead to dishonor and ignominy.
Backbiting and slandering are shame and disgrace. Their perpetrator is detested and he shall not have a noble death. Allah (swt) forbids these acts, Allah (swt) says in the Holy Quran:
"O you who have believed, avoid much [negative] assumption. Indeed, some assumption is sin. And do not spy or backbite each other. Would one of you like to eat the flesh of his brother when dead? You would detest it. And fear Allah ; indeed, Allah is Accepting of repentance and Merciful." Surat Al-Ĥujurāt 49:12
When one reflects deeply over this assimilation it will be enough to keep one away from backbiting. Furthermore Abu Hurrairah (r.a) narrates that the Holy Prophet Muhammed (saw) said :
"Do you know what backbiting is?” They said, “Allah and His Messenger know best.” He then said, “It is to say something about your brother that he would dislike.” Someone asked him, “But what if what I say is true?” The Messenger of Allah said, “If what you say about him is true, you are backbiting him, but if it is not true then you have slandered him."
This is because the backbiter if the wrongdoer and his victim is the wronged, on the Day of Resurrection both the wrongdoer and the wronged will stand before Allah Who is the Just Judge and the wronged will appeal to Allah to avenge the wrong done to him, Allah will then give this wronged person from the good deeds of the person who wronged him in accordance with his wrong by backbiting his brother on a Day that no father will give his son any of his good deeds nor a friend to his friend. All will be saying, ‘Myself, myself.’
So, fellow Muslim brothers and sisters in Islam, you should beware of slipping of your tongues and do not give it free hand to wreak havoc on you. For a too free tongue destroys its owner and causes him calamities and evils. Jazaak'allah Khair for reading.