He was asked:

About a well containing a large quantity of water into which a dog fell and died, remaining there until its skin and hair decomposed, without changing any quality of the water whatsoever—neither its taste, colour, nor smell.

He answered:

Praise be to Allah. According to the great majority of scholars—including Mālik, al-Shāfi‘ī, and Ahmad—the water is pure if it amounts to two qullahs, approximately two waterskins. How much more so if it exceeds that amount?

Scholars disagree about whether a dog’s hair is pure. It is pure according to Mālik’s school and impure according to al-Shāfi‘ī’s, while two opinions are reported from Ahmad. Thus, if it is not known that the bucket being drawn up contains any of the dog’s hair, it is undoubtedly not to be judged impure.

It is authentically reported that the Prophet, peace and blessings be upon him, was asked:

“O Messenger of Allah, you perform ablution with water from the well of Budā‘ah, although menstrual cloths, dog flesh, and human excrement are thrown into it?”

He replied:

“Water is pure and purifying; nothing renders it impure.”

The well of Budā‘ah is well known, situated in the eastern part of Medina, and still exists today. As for anyone who says: