Ruling 259
If the upper part of one’s foot is impure and it cannot be washed [and made pure] so that it can be wiped, then tayammum must be performed.
-Ayatullah Sistani, Practical Laws of Islam, Purification (Taharah)
Purity: Impurity of the Foot Preventing Wiping
Practical Laws of Islam as per the teachings of Ayatullah Sistani
