The Prophet (ﷺ) said: When a ruler seeks to make imputations against the people, he corrupts them.
Sunan Abi Dawud Book 43, Hadith 117
← Previous Hadith 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.

Sunan Abi Dawud Book 43, Hadith 116 Next Hadith → Zayd ibn Wahb said: A man was brought to Ibn Mas'ud. He was told: This is so and so, and wine was dropping from his beard. Abdullah thereupon said: We have been prohibited to seek out (faults). If anything becomes manifest to us, we shall seize it.

Sunan Abi Dawud Book 43, Hadith 118