Does water reaching the two Qullahs (a measure of volume) become impure?
Chapter on what purification is achieved with regarding water
Al-Mughni
Book of Purification
Primary text
There are two narrations concerning water amounting to two Qullahs. The prominent narration holds that it becomes impure by human urine. This is supported by the narration from Abu Hurayrah where the Prophet, peace be upon him, forbade urinating in still water from which one performs ghusl or wudu, which is considered specific to urine and is judged stronger than the Hadith of the two Qullahs, thus taking precedence. This ruling applies to both little and much urine.
Supporting text
The second narration, chosen by Abu al-Khattab and Ibn 'Aqil, aligns with the view of ash-Shafi'i and most scholars, maintaining that water does not become impure unless the impurity changes its characteristics, based on the Hadith, 'When water reaches two Qullahs, it is not rendered impure.' They argue that human urine is no worse than dog urine, which does not pollute two Qullahs, and that the Hadith of Abu Hurayrah must be restricted, perhaps to water that cannot be drained, or restricted by the Hadith of the two Qullahs, favoring restriction by explicit Prophetic text over analogical reasoning.