Sunan Abi Dawud 4876
سنن أبي داود#4876SahihNarrated Sa'id ibn Zayd: The Prophet (ﷺ) said: The most prevalent kind of usury is going to lengths in talking unjustly against a Muslim's honour
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Al-AlbaniSahih
Muhammad Muhyi Al-Din Abdul HamidSahih
Shuaib Al ArnautSahih
Zubair Ali ZaiIsnaad Sahih
In-book reference: 43:104