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.

حَدَّثَنَا عَبْدُ اللَّهِ بْنُ مُحَمَّدٍ النُّفَيْلِيُّ، حَدَّثَنَا أَبُو مُعَاوِيَةَ، عَنْ هِشَامِ بْنِ عُرْوَةَ، عَنْ عَمْرِو بْنِ خُزَيْمَةَ، عَنْ عُمَارَةَ بْنِ خُزَيْمَةَ، عَنْ خُزَيْمَةَ بْنِ ثَابِتٍ، قَالَ سُئِلَ رَسُولُ اللَّهِ ﷺ عَنْ الاِسْتِطَابَةِ فَقَالَ
" بِثَلاَثَةِ أَحْجَارٍ لَيْسَ فِيهَا رَجِيعٌ " . قَالَ أَبُو دَاوُدَ كَذَا رَوَاهُ أَبُو أُسَامَةَ وَابْنُ نُمَيْرٍ عَنْ هِشَامٍ يَعْنِي ابْنَ عُرْوَةَ .