Likewise, water used to remove ritual impurity retains its purifying capacity. It is authentically reported that the Prophet, may Allah bless him and grant him peace, said:

“Water does not become impure.”

Water therefore does not itself enter a state of major ritual impurity, nor does the ruling associated with that state pass to it. His prohibition—may Allah bless him and grant him peace—against urinating or bathing in standing water does not indicate that the water becomes impure as a result. Rather, he prohibited it because repeated urination eventually spoils the water, or because it leads to obsessive doubts. Similarly, he forbade a man to urinate where he bathes, saying:

“Most obsessive doubts arise from that.”

As for his prohibition against bathing, one report states that he prohibited bathing in the water after urinating in it. This resembles his prohibition against urinating where one bathes.

It is also established in an authentic hadith that the Prophet, may Allah bless him and grant him peace, was asked about a mouse that had fallen into clarified butter. He replied:

“Throw it away, along with what surrounds it, and eat your clarified butter.”

The distinction reported in the wording, “If it is solid, throw it away along with what surrounds it; but if it is liquid, do not go near it,” is an error, as al-Bukhārī, al-Tirmidhī and others have explained. It is an error made by Maʿmar in narrating this hadith.

Ibn ʿAbbās, who narrated it, ruled that if the mouse died, it and the surrounding butter should be discarded, and the rest could be eaten. It was said to them, “But it moved around in it.” He replied, “That was only while it was alive. Once it died, it stayed in one place.” Ahmad reported this in the Masāʾil (Legal Questions) of his son Sālih.

Likewise, al-Zuhrī, another narrator of the hadith, ruled that whether the substance was solid or liquid, small or large in quantity, and whether it was clarified butter, oil or something else, the mouse and whatever was close to it should be discarded, and the remainder could be eaten;