Fiqh-us-Sunnah Volume 1, Purification and Prayer, Fiqh 1.032D.

Anas said, “The Prophet, upon whom be peace, used to perform ghusl (the complete bathing) with a sa’a of water (1.616 cm) 3 to 5 madd (each 4 madd equals one sa’a). He also used to make ablution with one madd (404 cm) of water.” (Related by al-Bukhari and Musim.) ‘Ubaidullah ibn Abu Yazid narrated that a man asked Ibn ‘Abbas, “How much water is sufficient for ghusl?” He answered, “One madd.” “And how much is sufficient for ghusl?” He said, “One sa’a.” The man said, “That is not sufficient for me.” “Ibn ‘Abbas said, “No? It was sufficient for one better than you, the Messenger of Allah, upon whom be peace.” (Related by Ahmad, al-Bazaar and at-Tabarani in al-Kabeer. Its  narrators are trustworthy.) ‘Abdullah ibn ‘Umar narrated that the Messenger of Allah passed by Sa’d while he was performing ablution and said, “What is this extravagance, Sa’d?” He said, “Is there extravagance in the use of water?” He said, “Yes, even if you are at a flowing  river.” (Related by Ahmad and Ibn Majah with a weak chain.)

Extravagance is to use water without any benefit, like washing the parts  more than three times. Ibn Shu’aib’s hadith, quoted earlier, illustrates the point in question. ‘Abdullah ibn Mughaffal narrated that he heard the Prophet say, “There will be people from my nation who will transgress in making supplications and in purifying themselves.” (Related by Ahmad, Abu Dawud and an-Nasa’i.)

Says al-Bukhari, “The scholars do not like one to use water beyond what the Prophet, upon whom be peace, used for ablution.