Language:
كتاب الوضوء
4  
Ablutions (Wudu')
(47)
Chapter: To perform ablution with one Mudd of water. (Mudd is practically 2/3 of the kilogram)
(47)
باب الْوُضُوءِ بِالْمُدِّ
Sahih al-Bukhari 201

Narrated Anas:

The Prophet (ﷺ) used to take a bath with one Sa` up to five Mudds (1 Sa` = [??] Mudds) of water and used to perform ablution with one Mudd of water.

حَدَّثَنَا أَبُو نُعَيْمٍ، قَالَ حَدَّثَنَا مِسْعَرٌ، قَالَ حَدَّثَنِي ابْنُ جَبْرٍ، قَالَ سَمِعْتُ أَنَسًا، يَقُولُ كَانَ النَّبِيُّ صلى الله عليه وسلم يَغْسِلُ ـ أَوْ كَانَ يَغْتَسِلُ ـ بِالصَّاعِ إِلَى خَمْسَةِ أَمْدَادٍ، وَيَتَوَضَّأُ بِالْمُدِّ‏.‏
Reference : Sahih al-Bukhari 201
In-book reference : Book 4, Hadith 67
USC-MSA web (English) reference : Vol. 1, Book 4, Hadith 200
  (deprecated numbering scheme)