Bulugh al-Maram
Narrated Anas (rad): Allah’s Messenger (ﷺ) used only one Mudd of water for ablution and one Sa’ to five Mudd of water for his bath [ Agreed upon].
وَعَنْهُ قَالَ: { كَانَ رَسُولُ اَللَّهِ - صلى الله عليه وسلم -يَتَوَضَّأُ بِالْمُدِّ, وَيَغْتَسِلُ بِالصَّاعِ إِلَى خَمْسَةِ أَمْدَادٍ } مُتَّفَقٌ عَلَيْه ِ 1 .
Reference