Narrated Muawiyah رضي الله عنه (May Allah be pleased with him): I heard the Apostle of Allah صلى الله عليه وسلم (Peace be upon him) say: If you search for the faults of the people, you will corrupt them, or will nearly corrupt them. Abu Darda (May Allah be pleased with him) said: These are the words which Muawiyah himself heard from the Apostle of Allah (Peace be upon him), and Allah benefited him by them.

[Sunan Abu Dawood, Hadith no. 4888, Authentic]

Abu Barzah al-Aslami رضي الله عنه (May Allah be pleased with him) said: The Messenger of Allaah صلى الله عليه وسلم (Peace be upon him) said: O you who have spoken the words of faith but faith has not truly entered your hearts! Do not backbite about the Muslims, and do not seek out their faults. For whoever seeks out their faults, Allaah will seek out his faults, and if Allaah seeks out a person’s faults He will expose him even in his own house.’”

[Sunan Abu Dawood, Hadith no. 4880, Authentic]

Abu Hurayrah رضي الله عنه (May Allah be pleased with him) said that the Prophet صلى الله عليه وسلم (Peace be upon him) said: ‘Beware of suspicion, for suspicion is the falsest of speech. Do not eavesdrop; do not spy on one another; do not envy one another; do not forsake one another; do not hate one another. Be, O slaves of Allaah, brothers.”

[Sahi Bukhari, Hadith no. 5144]