Narrated to me by the Shaykh (Al-Mufid), may Allah سبحانه وتعالى support him, who said: Ahmad bin Muhammad bin Al-Hasan narrated to me, from his father, from Muhammad bin Al-Hasan and Sa'd bin Abdullah, from Ahmad bin Muhammad bin Isa and Al-Husayn bin Al-Hasan bin Aban, from Al-Husayn bin Sa'id, from Ibn Abi Umayr, from Abu Ayyub, from Muhammad bin Muslim, from Abu Abdullah عليه السلام, who was asked: (Narrator said) Imam عليه السلام was asked, 'What about water in which animals urinate, dogs lick, and a person in a state of janabah (major ritual impurity) bathes?' Imam عليه السلام said: 'If the water is equal to a kurr, nothing can make it impure.'