Narrated Abu Huraira:

That once he was in the company of the Prophet (ﷺ) carrying a water pot for his ablution and for cleaning his private parts. While he was following him carrying it (i.e. the pot), the Prophet (ﷺ) said, "Who is this?" He said, "I am Abu Huraira." The Prophet (ﷺ) said, "Bring me stones in order to clean my private parts, and do not bring any bones or animal dung." Abu Huraira went on narrating: So I brought some stones, carrying them in the corner of my robe till I put them by his side and went away. When he finished, I walked with him and asked, "What about the bone and the animal dung?" He said, "They are of the food of Jinns. The delegate of Jinns of (the city of) Nasibin came to me--and how nice those Jinns were--and asked me for the remains of the human food. I invoked Allah for them that they would never pass by a bone or animal dung but find food on them."