Musannaf Ibn Abi Shayba 1:1834

Shababa ibn Sawwar narrated to us, he said: Shu'bah narrated to us, from Abu al-Tayyah, he said: I heard Mutarrif narrating from Ibn al-Mughaffal that the Messenger of Allah (may Allah bless him and grant him peace) said: "If a dog laps from a vessel, then wash it seven times, and rub it with earth the eighth time."