The Messenger of Allah ﷺ passed by two graves and said, "Indeed, these two are being punished, and they are not being punished for something major. One of them used to walk about spreading slander, and the other did not shield himself from his urine."Then he called for a fresh palm branch, split it in two, and planted one piece on this grave and the other piece on that grave. He said, "Perhaps their punishment will be lightened so long as these do not dry out."
حدثني أبو سعيد الأشج وأبو كريب محمد بن العلاء وإسحق بن إبراهيم قال إسحق أخبرنا وقال الآخران حدثنا وكيع حدثنا الأعمش قال سمعت مجاهدا يحدث عن طاوس
مر رسول الله ﷺ على قبرين فقال أما إنهما ليعذبان وما يعذبان في كبير أما أحدهما فكان يمشي بالنميمة وأما الآخر فكان لا يستتر من بوله قال فدعا بعسيب رطب فشقه باثنين ثم غرس على هذا واحدا وعلى هذا واحدا ثم قال لعله أن يخفف عنهما ما لم ييبسا
Both of them (Bukhari and Muslim) related together the hadith of Amash, from Mujahid, from Tawus, from Ibn Abbas (concerning the story of the two graves, and that one of the two [occupants] used to fail to cleanse himself properly after urinating). Mansur differed with him and dropped Tawus from the chain. Bukhari alone related the hadith of Mansur alone, with Tawus dropped from it.
Hafiz, may Allah have mercy on him, said in the introduction (p. 350, printing S), after mentioning Daraqutni's statement, "Bukhari narrated this hadith in the Book of Purification from Uthman bin Abu Shayba from Jareer, and in the Book of Manners from Muhammad bin Salam from Ubayda, both of them from Mansur, with this wording. He also narrated it through another route from the hadith of Amash, and the remaining five imams narrated it from the hadith of Amash as well."Hafiz, may Allah have mercy on him, then said, "In reality this is not a defect, because Mujahid was not described as one who practiced tadlis, and his hearing from Ibn Abbas is sahih in a number of hadiths. Mansur, in their view, is more precise than Amash, though Amash is also among the memorizers of hadith. So however the hadith is traced, it traces back to a trustworthy narrator, and however the chain is traced, it remains connected. Something like this does not undermine the soundness of the hadith, so long as its narrator does not practice tadlis. The two Shaykhs (Bukhari and Muslim) frequently narrated things of this sort, and Daraqutni did not exhaustively cover his criticism. And Allah grants success." End of quote.Hafiz also said in Fath al-Bari, volume 1, page 317, printing S, "His narrating it in both forms indicates that he considered both of them sahih in his view. This is to be understood as meaning that Mujahid heard it from Tawus from Ibn Abbas, and then heard it from Ibn Abbas directly without an intermediary, or the reverse. This is supported by the fact that his wording from Tawus contains an addition beyond what is in his narration from Ibn Abbas. Ibn Hibban explicitly stated that both routes are sahih together." End of quote.