‘Umara bin Khuzaymah bin Thabit al-Ansari narrated from his father, Sayyiduna Khuzaymah (may Allah be pleased with him), that the Messenger of Allah (peace and blessings be upon him) said: “(Istinja) should be done with three stones, none of which should be dung.”
Narrated Khuzaymah ibn Thabit: The Prophet ﷺ was asked about cleansing (after relieving oneself). He said: (One should cleanse oneself) with three stones which should be free from dung. Abu Dawud said: A similar tradition has been narrated by Abu Usamah and Ibn Numair from Hisham.
Shaykh Umar Farooq Saeedi
Benefits and Issues: This narration is weak in its chain of transmission. However, in an authentic hadith, the prohibition of performing istinja (purification after relieving oneself) with dung and bones is established. [صحيح مسلم، حديث : 262] Most likely for this reason, Shaykh al-Albani rahimahullah has declared it authentic.
Source: Sunan Abu Dawood – Commentary by Shaykh Umar Farooq Saeedi, Page: 41
´It was narrated that Khuzaimah bin Thabit said:` "The Messenger of Allah said: 'For cleaning yourself you need three stones, no one of them being dung.'"
Maulana Ataullah Sajid
Commentary: The word (rajī‘) is used for dung, droppings, and human excrement alike. Here, it has been translated as dung and droppings because in other hadiths the word (rawth) is used, which refers specifically to the droppings of donkeys, horses, etc.
When using droppings and dung for istinja (ritual cleansing after relieving oneself) is prohibited, then the use of human excrement is, a fortiori, even more strictly prohibited. From the preceding narration, which is authentic, the prohibition of using dung and droppings is also established; therefore, in meaning, this narration is also authentic.
Source: Commentary on Sunan Ibn Mājah by Mawlānā ‘Atā’ullāh Sājid, Page: 315