Is the stipulation of washing seven times with earth obligatory for the impurity of a dog or pig?
Chapter on what purification is achieved with regarding water
Al-Mughni
Book of Purification
Primary text
The obligation of washing seven times, with one wash being with earth, is established by the report from Abu Hurairah that the Messenger of Allah, peace be upon him, said: 'If a dog laps in the vessel of one of you, let him wash it seven times,' and the narration to Abu Dawud and Muslim stating, 'The first of them with earth.' The report stating the eighth wash with earth is considered less sound due to the weakness of a narrator in that specific chain.
Supporting text
Abu Hanifa holds that a specific number is not obligatory for any impurity; rather, it must be washed until certainty of purity from the impurity is achieved. This is based on narrations indicating three, five, or seven washes without specifying a number, and the analogy to impurities on the ground where counting is not required. However, the ground is excused due to hardship (mashaqqah), unlike other surfaces.