There’s a reward for every kind of word we speak. Our aim must be to please Allah (SWT) by speaking kind words and avoiding bad words as much as we can. Gossip, backbiting, lying, using abusive words, or engaging in any words that can hurt the opposite person is a sin.
There’s a Hadith from Sahih Muslim 1009 which is as follows:
Hammam b. Munabbih reported that-this is out of (those ahadith) which Abu Huraira narrated to us from Muhammad, the Messenger of Allah (ﷺ). And he while making a mention of ahadith reported from Allah’s Messenger (ﷺ) said this:
Sadaqa is due on every joint of a person, every day the sun rises. Administering of justice between two men is also a Sadaqa. And assisting a man to ride upon his beast, or helping him load his luggage upon it, is a Sadaqa; and a good word is a Sadaqa; and every step that you take towards prayer is a Sadaqa, and removing of harmful things from the pathway is a Sadaqa.
It is recorded in a Hadith, that the good deeds of the backbiter are transferred to the account of the deeds of the victim. And all his bad deeds will be transferred into the account of the backbiter.
A Muslim must think about that on a serious note! No one would like to convert his/her good deeds into bad. The person will be responsible to guard his own tongue against speaking the words that are forbidden in Islam.