O ye who believe! Avoid suspicion as much (as possible): for suspicion in some cases is a sin: And spy not on each other behind their backs. Would any of you like to eat the flesh of his dead brother? Nay, ye would abhor it…But fear Allah: For Allah is Oft-Returning, Most Merciful.
Islam aims at establishing its society on clearness of conscience and mutual trust, not on doubts, suspicions, accusations and mistrust. Hence this ayah mentions the fourth prohibition by which what is to be held sacred among people is safeguarded: O you who believe, avoid (indulging in) much suspicion; truly some suspicion is a sin. (49:12)
The kind of suspicion which is a sin is the ascribing of evil motives, and it is not permissible for a Muslim to impute such motives to his brother Muslim without justification and clear evidence. Because the basic assumption concerning people is that they are innocent, a mere suspicion should not be allowed to result in the accusation of an innocent person. Regarding this the Prophet (peace be on him) said, “Avoid suspicion, for airing suspicion is the most lying form of speech.” (Reported by al-Bukhari and others.)
Human weakness is such that no one is free of suspicion and wrong thoughts especially concerning those with whom relationships are not good. However, one must not give in to such thoughts nor go beyond thoughts to action, as stated in the hadith, “If you have a suspicion, do not pursue it.” (Reported by al-Tabarani.)
Inwardly, mistrust of others produces evil thoughts in the mind while outwardly it leads a person toward spying. But Islam establishes its society on the purity of both what is inner and what is outer. Therefore, just as spying follows suspicion, the prohibition of spying comes immediately after that of suspicion.
Prying into other peoples’ private affairs and spying on their secrets is not permitted, even if they are engaged in sin, as long as they do it privately and not openly.
Abu Haitham, the scribe of ‘Uqbah bin ‘Amir, a Companion of the Prophet (peace be on him) narrated, “I said to ‘Uqbah bin ‘Amir, ‘Some of our neighbors drink wine, and I am going to call the police and have them arrested.’ He said, ‘Do not do so, but advise them and warn them.’ I said, ‘I told them to stop it but they do not listen to me. I am therefore going to inform the police and have them arrested.’ ‘Uqbah then said, ‘Woe to you! Do not do that, for I heard the Messenger of Allah (peace be on him) say, If one conceals the private affairs (of others), it is like reviving a girl who has been buried alive from her grave. (Reported by Abu Daoud’ al-Nisai, Ibn Hibban in his Sahih, and al-Hakim. The wording is from Ibn Hibban.)
The Prophet (peace be on him) classified those who search out other peoples’ faults as being among the hypocrites, who proclaim their belief with their tongues while their hearts do not confirm what they say. He denounced such people publicly. Ibn ‘Umar narrated, “Allah’s Messenger (peace be on him) mounted the pulpit and called out in a loud voice, O you who declare Islam with your tongues but whose hearts have not been reached by faith, do not annoy the Muslims nor seek out the* faults, for he who seeks out the faults of his brother Muslim will have his faults sought out by Allah, and when Allah seeks out someone’s faults, He exposes them, even though he should be in the interior of his house. (Reported by al-Tirmidhi, and Ibn Majah has reported something similar.)
In order to safeguard peoples’ privacy, the Prophet (peace be on him) strictly forbade that anyone should look into other peoples’ houses without their permission and absolved the residents for any injury they might inflict upon one who so looks. He said, If someone peeps into the house of a people without their permission, it becomes allowable to them to gouge out his eye. (Reported by al-Bukhari and Muslim.)
Likewise, he prohibited listening clandestinely to peoples’ conversation without their knowledge or approval, saying, He who listens clandestinely to peoples’ conversation against their wishes will have molten lead poured into his ears on the Day of Resurrection. (Reported by al-Bukhari and Muslim.)
Allah Subhanahu wa Ta’ala has made it obligatory on the person who wants to visit someone at his home not to enter the house until permission is given and he has greeted its inhabitants: O you who believe, do not enter houses other than your own until you have asked permission and offered salam (greeting) to its people; that is best for you in order that you may be heedful. And if you do not find anyone therein, do not enter until permission is given to you. And if you are to, ‘Withdraw,’ then do 60; that is purer for y; and Allah knows what you do. (24: 27-28)
Said the Prophet (peace be on him), He who pulls the curtain and l looks into a house before he is granted permission to E enter has committed an offense. (Reported by Ahmad and al-Tirmidhi.)
The texts prohibiting spying and searching out people’ faults apply equally to the government and to individuals. Mu’awiyah reported the Prophet (peace be on him) as saying, “If you seek out peoples’ faults, you will corrupt them, or bring them very near to corruption” (Reported by Abu Daoud and by Ibn Hibban in his Sahih.), and Abu Imamah reported that the Prophet (peace be on him) said, The ruler who sows suspicion among the people corrupts them. (Reported by Abu Daoud.)
Al-Qaradawi, Yusuf (1960). The Lawful and Prohibited in Islam. http://www.islamicweblibrary.com/wp-content/uploads/2019/06/TheLawfulAndTheProhibitedInIslamal-halalWalHaramFilIslamByShaykhYusufAlQardawi.pdf