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. (Using translation from Abū Dāʾūd 4888)
سَمِعْتُ رَسُولَ اللهِ ﷺ يَقُولُ إِنَّكَ إِنِ اتَّبَعْتَ عَوْرَاتِ النَّاسِ أَوْ عَثَرَاتِ النَّاسِ أَفْسَدْتَهُمْ أَوْ كِدْتَ أَنْ تُفْسِدَهُمْ قَالَ يَقُولُ أَبُو الدَّرْدَاءِ كَلِمَةٌ سَمِعَهَا مُعَاوِيَةُ مِنْ رَسُولِ اللهِ ﷺ فَنَفَعَهُ اللهُ بِهَا