The Messenger of Allah ﷺ was asked about a mouse that had fallen into clarified butter and died. He said, "If it is solid, take it out along with what surrounds it and eat the rest. But if it is liquid, do not eat it."
حدثنا محمد بن جعفر حدثنا معمر أخبرنا ابن شهاب عن ابن المسيب
سئل رسول الله ﷺ عن فأرة وقعت في سمن فماتت قال إن كان جامدا فخذوها وما حولها ثم كلوا ما بقي وإن كان مائعا فلا تأكلوه
Its isnad is sahih. It will come again with this same isnad at 10360. It will also come at 7591 from Abdul-Razzaq from Mamar. It will also come at 7591m, twice, with two isnads we will point out, Allah willing. Abu Dawud narrated it at 429:3/3842-430 (Awn al-Mabud), by way of Abdul-Razzaq from Mamar, with this wording.The scholars have differed of old concerning this isnad. Some held it to be sahih, and in our view it is sahih according to the standard of the two Shaykhs (Bukhari and Muslim). Others held it to contain a flaw, arguing that the correct attribution is that it is a hadith of Maymuna. Malik narrated it in Muwatta (p. 971-972) from Ibn Shihab, from Ubaydullah bin Abdullah bin Utba bin Masud, from Abdullah bin Abbas, from Maymuna, that the Messenger of Allah ﷺ was asked about a mouse falling into ghee, and he said, "Remove it and what is around it, and throw that away." This will come in the Musnad at 6:335h, by way of Malik. Bukhari narrated something similar at 296:1 with two isnads by way of Malik.Likewise, Sufyan bin Uyayna narrated it from Zuhri, with this isnad, as a hadith of Maymuna. This will come in the Musnad at 6:329h from Sufyan. Bukhari narrated it at 576:9-577 from Humaydi from Sufyan, and Humaydi then said, Sufyan was asked, "But Mamar narrates it from Zuhri from Saeed bin Musayab from Abu Hurairah." He said, "I never heard Zuhri say it except from Ubaydullah, from Ibn Abbas, from Maymuna, and I heard it from him many times."Tirmidhi narrated it at 80, from Saeed bin Abdul-Rahman and Abu Ammar, both of them from Sufyan. Tirmidhi then said, "Mamar narrated it from Zuhri from Saeed bin Musayab from Abu Hurairah from the Prophet, similarly, but this hadith is not well preserved. I heard Muhammad bin Ismail [that is, Bukhari] say, 'The hadith of Mamar from Zuhri from Saeed bin Musayab from Abu Hurairah from the Prophet, on this matter, is a mistake. The sahih version is the hadith of Zuhri from Ubaydullah from Ibn Abbas from Maymuna.'"Likewise, Ahmad narrated it at 6:330h by way of Uzai from Zuhri, matching the narration of Malik and Sufyan. Hafiz (Ibn Hajar) quoted in Fath al-Bari 1:296 from Dhahli in his Zuhriyat, who said, "Both routes are, in our view, well preserved, but the route of Ibn Abbas from Maymuna is more famous." He quoted something similar from him again at 9:577. This is the plain truth, about which there is no doubt.In my view, the source of all this alleged flaw is simply the statement of Sufyan bin Uyayna, as narrated by Bukhari, and it is not really a flaw at all. That is why Hafiz said in Fath al-Bari 9:577, "The fact that Sufyan bin Uyayna did not preserve it from Zuhri except by the route of Maymuna does not mean that he could not have had another isnad for it from Zuhri as well." Moreover, Mamar was among the people who preserved Zuhri's hadith most reliably. In Tahzib Sunan 10:244 it is stated, Ibn Abu Khaythama said, on the authority of Ibn Main, "Mamar is more reliable regarding Zuhri than Ibn Uyayna." Uthman Darimi said, "I asked Ibn Main, 'Is Mamar dearer to you regarding Zuhri, or Ibn Uyayna, or Salih bin Kaysan?' He said, in every instance, 'Mamar.'" Ghalabi said, "I heard Ibn Main give precedence to Malik bin Anas over the companions of Zuhri, and then to Mamar."Mamar had indeed preserved this hadith from Zuhri by both routes, the hadith of Abu Hurairah and the hadith of Maymuna. Abu Dawud narrated this hadith, as we have shown, from Ahmad bin Salih and Hasan bin Ali from Abdul-Razzaq, and then said, Hasan said, Abdul-Razzaq said, "Mamar sometimes narrated it from Zuhri from Ubaydullah bin Abdullah from Ibn Abbas from Maymuna from the Prophet ﷺ."Abu Dawud then narrated it at 3843 from Ahmad bin Salih, "Abdul-Razzaq narrated to us, Abdul-Rahman bin Buzuya informed us from Mamar from Zuhri from Ubaydullah bin Abdullah from Ibn Abbas from Maymuna." So Mamar preserved both routes, and the establishing of one of them does not negate the other, nor does it constitute a flaw in it. Indeed Mamar also preserved it by yet another isnad from Abu Hurairah, apart from the narration through Zuhri. This will come in the Musnad, after Ahmad's narration of it from Abdul-Razzaq from Mamar from Zuhri from Ibn Musayab from Abu Hurairah at 7591. Abdul-Razzaq said, "Abdul-Rahman bin Buzuya informed me that Mamar used to relate it with this isnad, and would say, 'The Messenger of Allah said.'" He [that is, Ibn Buzuya] also said, "Mamar narrated to us from Ayub from Ibn Sirin from Abu Hurairah."Abdul-Rahman bin Buzuya is trustworthy, as will come in his place. Hafiz has spoken at length about this matter in Fath al-Bari, in the two places we have pointed to. Hafiz bin Qayyim has also spoken at length about it in Tahzib Sunan, in hadith 3693, volume 5, pages 336-341.