´It was narrated from 'Abdullah bin Mas'ud:` "The Messenger of Allah went to the toilet and said: 'Bring me three stones.' So I brought him two stones and a piece of dung. He took the two stones and threw the dung away, saying: 'It is impure.'"
Hadith ReferenceSunan Ibn Majah / The Book of Purification and its Sunnah / Hadith: 314
Hadith Gradingالألبانی:صحيح | زبیر علی زئی:صحيح بخاري