—the Almighty’s words: “And those who guard their private parts, except with their spouses or those whom their right hands possess, for then they are not blameworthy.” (al-Muʾminūn 23:5–6)

5 – It is recommended to economize in the use of water for both wuḍūʾ and ghusl, for the Prophet ﷺ and ʿĀʾishah would bathe together, each scooping from a single vessel.
In one version reported by al-Bukhārī (250) it reads: “from a cup called al-farq,” and a qadah is a drinking vessel.
Al-Bājī said: the correct capacity was two sāʿs—or, according to the majority, three sāʿs.

6 – The ḥadith displays the Prophet’s gracious companionship with his family and his willingness to share in their activities, gladdening their hearts and removing formality.

7 – It also points to the virtue of the Prophet’s wives, especially the truthful one, the daughter of the truthful, for they conveyed to the ummah many legal rulings—above all the domestic matters that only a housemate can observe.