Sunan Abi Dawud 4888
سنن أبي داود#4888SahihNarrated Mu'awiyah: I heard the Messenger of Allah (ﷺ) say: If you search for the faults of the people, you will corrupt them, or will nearly corrupt them. AbudDarda' said: These are the words which Mu'awiyah himself from the Messenger of Allah (ﷺ), and Allah benefited him by them
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
Zubair Ali ZaiSahih
In-book reference: 43:116