Is it permissible to exceed the recommended quantity of water for Wudu (ablution)?
Chapter on Ghusl from Janabah (Major Impurity)
Al-Mughni
Book of Purification
Primary text
It is permissible to use more water than the measure of a Mud in Wudu and more than a Sa' in Ghusl (ritual bath). Aisha narrated that she and the Prophet (peace be upon him) would perform Ghusl from a single vessel called a 'Farq,' which equates to three Sa'. Anas reported that the Prophet (peace be upon him) would use between one Sa' and five Amdad for his Ghusl. These narrations support the permissibility of exceeding the minimum standard.
Supporting text
However, extravagance in water use and excessive overconsumption are disliked (makruh), based on narrations indicating disapproval, such as when the Prophet (peace be upon him) questioned Sa'd regarding his excessive use of water during Wudu, stating, 'Is there extravagance even in Wudu?' He also warned against the whisperings of water, citing a devil named 'Walahan,' and it was said that a man's lack of deep understanding is shown by his excessive fondness for water.