Musannaf Ibn Abi Shaybah 38998 — Washing the hand before putting it

Sayyiduna Ibn al-Mughaffal (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) ordered that dogs be killed, and said: "When a dog puts its mouth into a vessel, wash it seven times, and scour it with earth the eighth time." It is mentioned that the view of (Imam) Abu Hanifah is: Washing the vessel once is sufficient.