with its odour, purification with it remains permissible, because its change is due to proximity rather than mixing. But if what falls into it is something from which the water can be protected and which mixes with it, such as vinegar, saffron, and the like, [its purifying quality ceases, and ablution with it is not permissible. If none of its characteristics has changed, then one must distinguish: if what has fallen into it is something pure,] its purifying quality does not cease, and purification with it is permissible, whether the water is little or abundant. But if what falls into it is something impure, then one must distinguish: if the water is a small amount, less than two qullahs, the water becomes impure; but if it amounts to two qullahs or more, it remains pure and ablution with it is permissible. Two qullahs equal five water-skins, and weigh five hundred ratls. The evidence for this is what Ahmad ibn Abd Allah al-Salihi informed us: Abu Bakr Ahmad ibn al-Hasan al-Hiri informed us; Hajib ibn Ahmad al-Tusi informed us; Abd al-Rahim ibn al-Munib narrated to us; Jarir informed us, from Muhammad ibn Ishaq, from Muhammad ibn Jafar ibn al-Zubayr, from Ubayd Allah ibn Abd Allah ibn Umar, from his father, that the Prophet, peace and blessings be upon him, was asked about water in the open desert to which animals and beasts of prey come. He said: “When water amounts to two qullahs, it is not rendered impure.” (2)

This is the view of al-Shafii, Ahmad, Ishaq, and a group of hadith scholars: when water reaches this amount, it is not rendered impure by impurity falling into it, unless one of its characteristics changes. (3)

Another group held that a small amount of water is not rendered impure by impurity falling into it unless its taste, colour, or smell changes. This was the view of al-Hasan, Ata, al-Nakhai, and al-Zuhri. They cited as evidence what Abu al-Qasim ibn Abd Allah ibn Muhammad al-Hanafi informed us: Abu al-Harith Tahir ibn Muhammad al-Tahiri informed us; Abu Muhammad al-Hasan ibn Muhammad ibn Hakim narrated to us; Abu al-Muwajjih Muhammad ibn Amr ibn al-Muwajjih narrated to us; Sadaqah ibn al-Fadl ⦗47/a⦘ informed us; Abu Usamah informed us, from al-Walid ibn Kathir, from Muhammad ibn Kab al-Qurazi, from Abd Allah ibn Abd al-Rahman ibn Rafi ibn Khadij, from Abu Said al-Khudri, who said: It was said, “O Messenger of Allah, may we perform ablution from the well of Budaah? It is a well into which menstrual cloths, dog carcasses, and putrid matter are thrown.” The Messenger of Allah, peace and blessings be upon him, said: “Water is purifying; nothing renders it impure.” (4)