Language:
كتاب الوضوء
4  
Ablutions (Wudu')
(46)
Chapter: To perform ablution from an earthen-ware pot
(46)
باب الْوُضُوءِ مِنَ التَّوْرِ
Sahih al-Bukhari 200

Narrated Thabit:

Anas said, "The Prophet (ﷺ) asked for water and a tumbler with a broad base and no so deep, containing a small quantity of water, was brought to him whereby he put his fingers in it." Anas further said, ' noticed the water springing out from amongst his fingers." Anas added, ' estimated that the people who performed ablution with it numbered between seventy to eighty."

حَدَّثَنَا مُسَدَّدٌ، قَالَ حَدَّثَنَا حَمَّادٌ، عَنْ ثَابِتٍ، عَنْ أَنَسٍ، أَنَّ النَّبِيَّ صلى الله عليه وسلم دَعَا بِإِنَاءٍ مِنْ مَاءٍ، فَأُتِيَ بِقَدَحٍ رَحْرَاحٍ فِيهِ شَىْءٌ مِنْ مَاءٍ، فَوَضَعَ أَصَابِعَهُ فِيهِ‏.‏ قَالَ أَنَسٌ فَجَعَلْتُ أَنْظُرُ إِلَى الْمَاءِ يَنْبُعُ مِنْ بَيْنِ أَصَابِعِهِ، قَالَ أَنَسٌ فَحَزَرْتُ مَنْ تَوَضَّأَ مَا بَيْنَ السَّبْعِينَ إِلَى الثَّمَانِينَ‏.‏
Reference : Sahih al-Bukhari 200
In-book reference : Book 4, Hadith 66
USC-MSA web (English) reference : Vol. 1, Book 4, Hadith 199
  (deprecated numbering scheme)