Sahih al-Bukhari 201
Sahih al-Bukhari · Book 4: Ablutions (Wudu') · To perform ablution with one Mudd of water. (Mudd is practically 2/3 of the kilogram)
Narrated Anas:
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.
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.