Allah has said: “And spy not, neither backbite against one another. Would any of you like to eat the flesh of his dead brother? You would hate it (so hate backbiting). And fear Allah. Verily Allah is the One Who accepts repentance, Most Merciful.” (49:12)
“And follow not that of which you have no knowledge. Verily! The hearing, and the sight, and the heart of each of those ones will be questioned.” (17:36)
“Not a word does he (or she) utter, but there is watcher by him ready (to record it).” (50:18)
Abu Musa narrated it: “Some people asked Allah’s Messenger (peace be upon him), whose Islam is the best?“ (i.e., who is a very good Muslim?)
The Prophet (peace be upon him) replied, “One who avoids harming the Muslims with his tongue and hands.”
“And the person may utter a word which displeases Allah without thinking how serious it is, as a result of which Allah will record His wrath for him, because of His displeasure until the Day when he meets Him.” (Related by Mu’atta Imam Malik and Tirmidhi).

