The Messenger of Allah ﷺ said, "Whoever eats a meal and then says, 'Praise be to Allah who has fed me this and provided it for me without any power or strength on my part,' his past sins will be forgiven."
قال رسول الله ﷺ: من أكل طعاما فقال: الحمد لله الذي أطعمني هذا ورزقنيه من غير حول مني ولا قوة، غفر له ما تقدم من ذنبه.
Tirmidhi narrated it (3458), Ibn Majah (3285), Ahmad (15632), Ibn Sunni (468), and Hakim (1/507), all through the route of Saeed bin Abu Ayub, who said, "Abu Marhum Abdul-Rahim bin Maymun narrated to me, from Sahl bin Muaz bin Anas, from his father," and he related it.Tirmidhi said, "This is a hasan gharib hadith." Hakim said, "This is a sahih hadith according to the criterion of Bukhari, though neither of them (Bukhari and Muslim) narrated it."I say, this is an error on his part, for Bukhari did not narrate from Abu Marhum, who is Abdul-Rahim bin Maymun, about whom there is disagreement, though his hadith is hasan. Likewise Sahl bin Muaz bin Anas, Bukhari did not narrate from him in his Sahih, but rather narrated from him in Adab al-Mufrad, and Hakim does not distinguish between the Sahih and Adab al-Mufrad.Then Sahl bin Muaz bin Anas is also disputed. Tirmidhi graded his hadith hasan, and Hakim graded it sahih, and Ajli said, "An Egyptian successor, trustworthy." Bukhari mentioned him in Tarikh al-Kabir, and quoted from Ibn Lahia that he was from the people of Syria, without commenting on him further. Ibn Hibban fell into inconsistency regarding him, mentioning him in Thiqat, and saying, "His hadith is not to be relied upon when it comes through the narration of Zabban bin Fayd from him." Yet he mentioned him again in Majruhin and said, "His hadith is very much rejected." Ibn Abu Hatim quoted in Jarh wa Tadil (4/204) from Abu Bakr bin Abu Khaythama, who said, in what he wrote to me, "I heard Yahya bin Main say, 'Sahl bin Muaz bin Anas, from his father, is daif.'"He thus mentioned his disparagement in a general, unqualified way, and for this reason most compilers did not accept Ibn Main's statement. Nawawi, in Adhkar, affirmed Tirmidhi's statement that it is hasan, and Ibn Hajar also graded it hasan in Nataij Afkar (1/120), and in Marifat Khisal Mukaffirah (pp. 74–75), where he said, "Sahl bin Muaz bin Anas Juhani, the Egyptian, is a well-known successor, truthful." Perhaps Ibn Main weakened him with respect to a specific chain, from his father, which contains an objectionable element, and so Ibn Abu Hatim stated it without qualification, and others followed him in that.Then I found Ibn Main's statement in Tarikh Ibn Abu Khaythama (2217), where he said, "Muhammad bin Ala Abu Kurayb narrated to us, Rashid bin Saad narrated to us, from Zabban bin Fayd, from Sahl bin Muaz bin Anas, from his father, who said, the Messenger of Allah ﷺ said, 'When you hear the muezzin repeating the call to prayer, say as he says.'" Yahya bin Main was asked about Ibn Muaz bin Anas, from his father, from the Prophet ﷺ, and he said, "Daif." Daraqutni said, "Zabban bin Fayd narrates a collection from Sahl bin Muaz bin Anas Juhani, from his father."Mizzi mentioned it in his Tahdhib, from Abu Bakr bin Abu Khaythama, from Yahya bin Main, "Daif," stated thus without qualification, without restricting it to "from his father."So the conclusion regarding him is that when Zabban bin Fayd narrates from Sahl bin Muaz, from his father, this is the case that is considered daif according to Ibn Main.Abu Dawud narrated it (4023) through the route of Saeed bin Ayub with the same chain, and its wording reads, "... his past and future sins will be forgiven." The addition of "future" was not narrated by most of those who transmitted this hadith, so it is an irregular addition.