Allaah, Exalted is He, says: “O you who believe, avoid much suspicion for indeed much suspicion is sin. Do not spy on each other …”
This noble verse contains the command to steer clear of much suspicion and highlights that much suspicion is sin. It also prohibits spying: searching and hunting for the mistakes and defects of people. This only comes about as a result of evil suspicion.
Bukhari and Muslim record that the Messenger of Allaah, peace and blessings be upon him, said, “Beware of suspicion for suspicion is the most false of speech. Do not hunt for faults in others, do not spy, do not be envious of each other, do not hate each other, and do not turn your backs on each other, but be servants of Allaah as brothers.”
The Leader of the Believers, ‘Umar bin al-Khattab, may Allaah be pleased with him, said, “Think only well of a word that leaves your believing brother so long as you find a way of understanding it in a good way.” This was quoted by ibn Kathir in his commentary to the above verse.
Bakr bin ‘Abdullah al-Muzani said, as quoted of him in his biography in Tadhib at-Tadhib , “Beware of a type of speech which you are correct in, you would not be rewarded, and if you are wrong, you would be sinful: evil suspicion of your brother.”
Abu Qilabah ‘Abdullah bin Zayd bin al-Jurmi said, as quoted in Abu Nu’aym, al-Hilyah, “If something of your brother is conveyed to you that you dislike, expend all your efforts in finding an excuse for him’ even then, if you cannot find an excuse say to yourself: perhaps he has an excuse that I am not aware of.”
Sufyan bin Husayn said, “I mentioned a person in a bad way in the presence of Iyas bin Mu’awiyah and he looked at my face and said , “Have you fought the people of Sind, the people of Hind, or the Turks?” I replied, “No.” He said, “[The kuffar] of Sind, Hind and the Turks are safe from you but your own Muslim brother is not!” So I never repeated what I said again.” [Recorded in ibn Kathir, al-Bidayah wa’l Nihayah.]
Abu Hatim bin Hibban al-Busti, Rawdatu’l-‘Uqala, said, “It is obligatory upon the intelligent to adhere firmly to safety by leaving spying and hunting for the faults of people, and busying himself with correcting his own faults. Whoever is busied by his own faults away from hunting for the faults of others will bring relief to his body and will not exhaust and trouble his heart. This is because each time a person finds a fault in himself, it will be easier for him to bear the same fault he sees in his Muslim brother. However the one who busies himself with hunting for the faults of people rather than his own will find his heart becoming blind and his body becoming weary, for he will find the excuse to ignore his own defects.”
He also said, “Spying is one of the branches of hypocrisy just as having good opinion is one of the branches of faith. The intelligent person makes good his opinion of his brothers, and concerns himself with his own problems and afflictions. The ignoramus thinks ill of his brothers and does not think of his own crimes and problems.”