Musnad Abu Ya'la al-Mawsili 105:10

Muhammad ibn Abi Bakr narrated to us, Thabit ibn Hammad Abu Zayd narrated to us, Ali ibn Zayd narrated to us, from Sa'id ibn al-Musayyib, from Ammar, who said: The Messenger of Allah (peace and blessings of Allah be upon him) passed by me while I was watering a she-camel of mine. I spat, and my spittle landed on my garment. I began to wash my garment from the leather water container that was before me. The Prophet (peace and blessings of Allah be upon him) said: "O Ammar, your spittle and the tears of your eyes are only in the status of the water that is in your leather container. You only wash your garment from urine, excrement, semen, the major fluid (madhy), blood, and vomit."