Bulugh al-Maram
The Book of Purification — Hadith #119
وَعَنِ ابْنِ مَسْعُودٍ - رضى الله عنه - قَالَ: { أَتَى اَلنَّبِيُّ - صلى الله عليه وسلم -اَلْغَائِطَ, فَأَمَرَنِي أَنْ آتِيَهُ بِثَلَاثَةِ أَحْجَارٍ, فَوَجَدْتُ حَجَرَيْنِ, وَلَمْ أَجِدْ ثَالِثًا. فَأَتَيْتُهُ بِرَوْثَةٍ. فَأَخَذَهُمَا وَأَلْقَى اَلرَّوْثَةَ, وَقَالَ:
"هَذَا رِكْسٌ" } أَخْرَجَهُ اَلْبُخَارِيّ ُ 1 .1 - صحيح. رواه البخاري (156).
The Prophet (ﷺ) went out to answer the call of nature and asked me to bring three stones. I found two stones and searched for the third but could not find it. So I took a dried piece of dung and brought it to him. He took the two stones and threw away the dung and said, “This is a filthy thing”.