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.  

سَمِعْتُ رَسُولَ اللَّهِ ﷺ يَقُولُ إِنَّكَ إِنِ اتَّبَعْتَ عَوْرَاتِ النَّاسِ أَفْسَدْتَهُمْ أَوْ كِدْتَ أَنْ تُفْسِدَهُمْ فَقَالَ أَبُو الدَّرْدَاءِ كَلِمَةٌ سَمِعَهَا مُعَاوِيَةُ مِنْ رَسُولِ اللَّهِ ﷺ نَفَعَهُ اللَّهُ تَعَالَى بِهَا  

The Prophet ﷺ said: When a ruler seeks to make imputations against the people, he corrupts them.  

عَنِ النَّبِيِّ ﷺ قَالَ إِنَّ الأَمِيرَ إِذَا ابْتَغَى الرِّيبَةَ فِي النَّاسِ أَفْسَدَهُمْ  

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.  

عَنِ التَّجَسُّسِ وَلَكِنْ إِنْ يَظْهَرْ لَنَا شَىْءٌ نَأْخُذْ بِهِ