It was narrated from Ibn Abi Sa’eed Al-Khudri that his father said:
“I passed by the Prophet (peace be upon him) when he was performing Wudu’ from the well of Buda’ah. I said: ‘Are you performing Wudu’ from it when garbage is thrown into it?’ He said: ‘Water is not made impure by anything.'”
(Nasa’i Vol. 1, Book 2, Hadith 328)
