The Prophet ﷺ went out to relieve himself and said, "Find me three stones."I brought him two stones and a piece of dung. He took the two stones and threw away the dung, saying, "It is filth."
حدثنا هناد وقتيبة قالا حدثنا وكيع عن إسرائيل عن أبي إسحق عن أبي عبيدة
خرج النبي ﷺ لحاجته فقال التمس لي ثلاثة أحجار قال فأتيته بحجرين وروثة فأخذ الحجرين وألقى الروثة وقال إنها ركس
[Sahih] Ahmad also reported it (11/388) from Waki with the same wording. Ahmad (1/450) and Ibn Khuzayma (no. 70) added, in the hadith of Alqama bin Qays from Ibn Masud, who reported it as a saying of the Prophet, "It is filth, bring me a stone." Its chain is daif, since Abu Ishaq narrated from Alqama using the ambiguous "an" formula. The hadith of Zuhayr [reported by Bukhari, Wudu, chapter, "One should not clean himself with dung," no. 156].The report of Abu Ubayda stating that he did not hear from his father has a sahih chain, and likewise the statement of Abdul-Rahman bin Mahdi, its chain is sahih, and the statement of Ahmad, its chain is sahih.