The Messenger of Allah ﷺ said, "When a man commits adultery, faith departs from him and hovers over him like a canopy. When he ceases from it, faith returns to him."
قال رسول الله ﷺ: إذا زنى الرجل خرج منه الإيمان كان عليه كالظلة، فإذا انقلع رجع إليه الإيمان.
Abu Dawud (4690) narrated it from Ishaq bin Suwayd Ramli, who said, Ibn Abu Maryam narrated to us, Nafi, meaning Ibn Zayd, informed us, he said, Ibn Hadi narrated to me, that Saeed bin Abu Saeed Maqburi narrated to him, that he heard Abu Hurairah, and he mentioned the hadith. Its isnad is sahih, and Hakim also graded it sahih (22/1) according to the standard of the two Shaykhs, saying, "Both of them relied on its narrators."As for what was narrated from Abu Hurairah as a marfu report, "Whoever commits adultery and drinks wine, Allah strips faith from him just as a man pulls a shirt off over his head," it is daif. Hakim narrated it (22/1) through two routes from Abu Abdul-Rahman Muqri, who said, Saeed bin Abu Ayub narrated to us, Abdullah bin Walid narrated to us, from Ibn Hujayra, that he heard Abu Hurairah, and he mentioned something similar.Hakim said, "Muslim relied on Abdul-Rahman bin Hujayra and Abdullah bin Walid, and both of them are Syrians."I say, this is an error on his part, for Abdullah bin Walid, who is Ibn Qays Tujaybi, the Egyptian, is not among the narrators of Muslim. Rather, Abu Dawud and Nasai narrated from him, and Ibn Hibban mentioned him in Thiqat, but Daraqutni declared him daif and said, "His hadith is not to be relied upon." And in Taqrib it says, "Weak in hadith." His teacher is actually Abdullah bin Abdul-Rahman bin Hujayra, not Abdul-Rahman bin Hujayra as Hakim said, so perhaps "from his father" was dropped from the isnad. Abdullah bin Abdul-Rahman bin Hujayra is also not among the narrators of Muslim. He narrated from his father, and Abdullah bin Walid Tujaybi narrated from him, and he too is among those whom Ibn Hibban deemed trustworthy.On this subject there is also a report from Jabir. Imam Ahmad narrated it (14731) from Musa, who said, Ibn Lahia narrated to us, from Abu Zubayr, that he said, I asked Jabir, "Did you hear the Prophet ﷺ say, 'The fornicator does not commit fornication while he is a believer, and the thief does not steal while he is a believer'?" Jabir said, "I did not hear it." Then Jabir said, "But Ibn Umar informed me that he did hear it."In the isnad is Ibn Lahia, about whom there is well-known discussion that he was weakened due to the confusion of his memory in his later years, and Musa, who is Ibn Dawud, is not among those who heard from him before that confusion set in.Tirmidhi said (16/5), after narrating the hadith of Abu Hurairah, "We do not know of anyone who declared another an unbeliever for fornication, theft, or drinking wine." And he said, "It has been narrated from Abu Jafar Muhammad bin Ali that he said, 'He exits from faith into Islam.'"