When a dog drinks from the vessel of any of you, let him wash it seven times

Abu Hurayrah (may Allah be pleased with him) reported: The Messenger of Allah (may Allah's peace and blessings be upon him) said: "When a dog drinks from the vessel of any of you, let him wash it seven times."

The Prophet (may Allah's peace and blessings be upon him) ordered that a vessel be washed seven times if a dog puts its tongue into it. The first of these times should be accompanied by dirt, followed by water, so that it is completely clean from its impurity and harm.