The Prophet ﷺ said, "Whoever breaks his fast during the month of Ramadan out of forgetfulness owes neither a make-up fast nor an expiation."
أن النبي ﷺ قال: من أفطر في شهر رمضان ناسيا فلا قضاء عليه، ولا كفارة.
No references are available.
Ibn Khuzayma (1990) narrated it from Muhammad and Ibrahim, the two sons of Muhammad bin Marzuq. Ibn Hibban (3521) narrated it from him through Ibrahim alone, and Daraqutni (2243), and Tabarani in Awsat (5342) narrated it through Muhammad bin Muhammad bin Marzuq alone, who said, Muhammad bin Abdullah Ansari told us, Muhammad bin Amr told us, from Abu Salama, from Abu Hurairah, and he mentioned it. Muhammad bin Muhammad bin Marzuq Bahili Basri is sometimes attributed to his grandfather, and he is among the men of Muslim. Daraqutni said, "Ibn Marzuq alone transmitted it, and he is trustworthy, from Ansari." I say, rather Abu Hatim Muhammad bin Idris followed him in this, and through his route Hakim narrated it (1/430), and from him Bayhaqi (4/229), from Muhammad bin Abdullah Ansari, and he mentioned it. Hakim said, "Sahih according to the standard of Muslim, though the two of them did not include it with this wording." Bayhaqi said, "Likewise Muhammad bin Marzuq Basri narrated it, from Ansari, and this is something Ansari alone transmitted from Muhammad bin Amr, and all of them are trustworthy." I say, Muhammad bin Amr is Ibn Alqama Laythi, whose hadith is hasan.This hadith has been narrated from Abu Hurairah through other chains, most of which are daif, and the one I have mentioned is the soundest of them.On this subject there is also what has been reported from Umm Ishaq, that she was with the Messenger of Allah ﷺ, and a bowl of tharid was brought, and she ate with him, and Dhul-Yadayn was with him. The Messenger of Allah ﷺ handed her a piece of meat and said, "O Umm Ishaq, take some of this." She then remembered that she was fasting, so her hand froze and she neither brought it forward nor drew it back. The Messenger of Allah ﷺ said, "What is wrong with you?" She said, "I was fasting and forgot." Dhul-Yadayn said, "Now, after you have already eaten your fill." The Prophet ﷺ said, "Complete your fast, for it is only provision that Allah has sent your way."Imam Ahmad narrated it (27069), Tabarani in Kabir (25/169), and Abd bin Humayd (1590), all of them from the hadith of Bashshar bin Abdul-Malik, who said, my grandmother Umm Hakeem bint Dinar, the freedwoman of Umm Ishaq, told me, from Umm Ishaq, and she mentioned it. Bashshar bin Abdul-Malik is Muzani Basri, whom Ibn Main declared daif, while Ibn Hibban regarded him as trustworthy. Ibn Hibban said that Umm Hakeem narrated from Umm Ishaq and had companionship with the Prophet. As for Umm Hakeem bint Dinar, no narrator has been mentioned to have transmitted from her other than Bashshar bin Abdul-Malik. Both of them are among the men of Tajil. Haythami said in Majma (3/157), "In it is Umm Hakeem, for whom I found no biography."On this subject there is also what has been reported from Abu Saeed Khudri, who said, the Messenger of Allah ﷺ said, "Whoever eats during the month of Ramadan forgetfully owes no makeup fast, for Allah has fed him and given him drink." Daraqutni narrated it (2240), and Tabarani in Awsat (6361), both through the route of Fazari, from Atiya, from Abu Saeed, and he mentioned it. Daraqutni said, Fazari here is Muhammad bin Ubaydullah Arzami. I say, this Arzami is daif by unanimous agreement of the scholars, and Daraqutni himself declared him daif. Ibn Hibban said, "His memory was poor, and his books were lost, so he began narrating from memory among them, and there came to be many objectionable narrations in his transmission." Hakim said, "His hadith is to be abandoned." Haythami criticized it for this reason in Majma (3/157), so someone like him cannot serve as a corroborating witness, and I have only mentioned it so that it be known.The apparent meaning of the hadith indicates that whoever eats or drinks forgetfully owes no makeup fast, and his fast remains sound. This is supported by the words of Allah Almighty, "Our Lord, do not hold us accountable if we forget or make a mistake" [Baqarah 2:286], and this is the view of the generality of the scholars, among them Sufyan Thawri, Shafii, Ahmad, and Ishaq. Malik said, if one eats during Ramadan forgetfully, he must make up the fast. Tirmidhi said, "The first view is more sahih." I say, Malik, may Allah have mercy on him, may be excused, for perhaps this hadith did not reach him.Whoever sees a fasting person eating or drinking should remind him and not leave him be, because of the mutual cooperation in righteousness and piety this involves, and also because it constitutes correcting a wrong, since eating and drinking during the month of Ramadan is among the gravest wrongs.As for one who has intercourse with his wife forgetfully during the day in Ramadan, the scholars have differed on this. Shafii and the people of Kufa held the same view as they did regarding one who eats or drinks forgetfully. Malik said he must make up the fast. Ahmad said he must make up the fast and pay the expiation. Each view has detailed evidence found in the books of jurisprudence, and for more, see Minna Kubra (3/319).