بسم الله الرحمن الرحيم
Muawiyah narrated that 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] Muawiya became on of the rulers in Islam, in charge people and their lives, the prophet (saws) knew this would occur and told him to be lenient and merciful during his rule and this was the other advice the prophet (saws) gave him.
Allah commands in the Quran, “O you who believe avoid much (negative) assumption. Indeed some assumption is sin. And do not spy or backbite each other, Would one of you like to eat the flesh of his brother when dead? You would detest it. (49:12).
The Prophet (saws) said, as narrated in Sahih Muslim: Do not envy one another, do not argue with one another, do not have hatred for one another and do not show your back to one another. Do not intervene in your brother’s transactions but be servants of Allah, brothers. A Muslim is the brother of a Muslim. He never oppresses him, never puts him down and never humiliates him. Sincerity is here, said the Prophet (saws), pointing to his heart. Anyone is evil if he will humiliate his Muslim Brother. Everything between Muslims is sacrosanct; his money and his honour.
Abu Huraira reported Allah’s Messenger (saws) as saying: Avoid suspicion, for suspicion is the gravest lie in talk and do not be inquisitive about one another and do not spy upon one another and do not feel envy with the other, and nurse no malice, and nurse no aversion and hostility against one another. And be fellow-brothers and servants of Allah. (Muslim)
Abu Hurayra reported that the Messenger of Allah, may Allah bless him and grant him peace, said, “Beware of opinion. Opinion is the most lying form of speech. Do not try to ensnare one another (in sales) nor envy one another nor hate one another nor shun one another. Rather be the slaves of Allah and brothers.” (Al Adab Al Mufrad)
Anas ibn Malik reported that the Messenger of Allah, may Allah bless him and grant him peace, said, “Do not hate one another nor envy one another nor shun one another. Slaves of Allah, be brothers! It is not lawful for a Muslim to refuse to speak to his brother (Muslim) for more than three nights.” (Al Adab Al Mufrad)