Muhammad ibn Ahmad ibn Yahya narrated from Abu Ja'far, from his father, from Hafs ibn Ghiyath, from Imam Ja’far Al Sadiq عليه السلام, from his father Imam Al Baqir عليه السلام, from Imam Ali عليه السلام. He said: Imam عليه السلام said: "I do not mind whether it is urine or water that touches me, as long as I do not know (with certainty)."