The Shaykh (Al-Mufid), may Allah سبحانه وتعالى support him, narrated to me from Abu al-Qasim Ja'far ibn Muhammad, from Muhammad ibn Ya'qub, from Abu Dawud, from al-Husayn ibn Sa'id, from his brother al-Hasan, from Zur'ah, from Sama‘ah, who said: I asked Imam عليه السلام: "Can the leftover water (su’r) of any of the animals be drunk or used for Wudu' (ablution)?" Imam عليه السلام said: "As for camels and cows, there is no harm."