What is the ruling when water used in washing an impurity (before completing seven washes) touches another location?
Chapter on what purification is achieved with regarding water
Al-Mughni
Book of Purification
Primary text
There are two opinions regarding water flowing from one impure area to another before the first area has been washed seven times. The first opinion mandates that the newly touched area must also be washed seven times. This view is apparent in the statements of Al-Khiraqi and is chosen by Ibn Hamid. The reasoning is that the transferred substance is an impurity, and its ruling is not dependent on the place it originated from, similar to impurities from the ground or the place of Istinja (cleansing after defecation/urination). Furthermore, if the original area was cleaned with dust (as required for dog saliva impurity), the new location must also be cleaned with dust, as it is an impurity that has touched an area other than the ground, resembling the initial instance.
Supporting text
The second opinion dictates that the subsequent area must be washed a number of times corresponding to the remaining washes required for the original area (e.g., if the first area required six more washes, the second needs five, and so on). This is because the transferred impurity is undergoing purification in its place, and since the first place is purified without seven washes (in the context of the initial contamination), it purifies an equally affected location, similar to impurity on the ground. The transferred substance is part of the connected whole, and since the connected whole is purified in this manner, so too is the detached part. This differs from impurities detached from the ground or Istinja area because the leniency there is due to the nature of the surface, which is absent here; the leniency here is due to the partial effect of the previous washes. If the transferred water came from an area washed with dust, the new area is washed without dust, and vice versa. This second view is chosen by Al-Qadi and is considered more sound.