The Prophet (ﷺ) said: The gravest sin is going to lengths in talking unjustly against a Muslim's honour, and it is a major sin to abuse twice for abusing once.
Sunan Abi Dawud Book 43, Hadith 105
← Previous Hadith The Prophet (ﷺ) said: The most prevalent kind of usury is going to lengths in talking unjustly against a Muslim's honour.

Sunan Abi Dawud Book 43, Hadith 104 Next Hadith → The Prophet (ﷺ) said: When I was taken up to heaven I passed by people who had nails of copper and were scratching their faces and their breasts. I said: Who are these people, Gabriel? He replied: They are those who were given to back biting and who aspersed people's honour.

Abu Dawud said: Yahya b. 'Uthman has also transmitted it from Baqiyyah, there is no mention of Anas in it.

Sunan Abi Dawud Book 43, Hadith 106