Is Tayammum valid if performed while a person still has an external impurity (Najasah) on their body that they can remove?
Chapter on the Obligation of Purification
Al-Mughni
Book of Purification
Primary text
The majority opinion holds that Tayammum is invalid if a person has a removable impurity elsewhere on their body besides the private parts. This is because Tayammum is only permitted for prayer; a person capable of removing an impurity is not permitted to pray, thus invalidating the intention to use Tayammum for that purpose, analogous to intending Tayammum before the prescribed time for prayer.
Supporting text
A second view suggests that Tayammum remains valid because it is a form of purification, similar to Wudu. Preventing the permissibility of prayer due to another impediment (the impurity) does not invalidate the validity of the Tayammum itself, similar to performing Tayammum in a forbidden place or when having an impurity on one's clothing or non-private body parts. However, distinguishing between impurities on the private parts and elsewhere is considered more appropriate, as impurity of the private parts is the direct cause necessitating Tayammum, potentially making its continuation a direct barrier to its validity.