He used to perform ablution with a mudd of water and bathe with about a saa.
أخبرنا هارون بن إسحق الكوفي قال حدثنا عبدة يعني ابن سليمان عن سعيد عن قتادة عن صفية بنت شيبة
كان يتوضأ بمد ويغتسل بنحو الصاع
[Sahih] Reported by Abu Dawud in the Book of Purification, chapter on what suffices of water for wudu, hadith no. 92, and Ibn Majah in the Book of Purification, chapter on what has been said regarding the amount of water for wudu and ghusl from janaba, hadith no. 268, from the narration of Qatada with this chain, and it has supporting narrations in Bukhari, Muslim, and others.