Purity: Ruling on Purification of Sole of Foot or Shoe by Asphalt, Wood, or Walls

Practical Laws of Islam as per the teachings of Ayatullah Sistani

Ruling 178

Based on obligatory precaution, the impure sole of one’s foot or shoe does not become pure by walking on asphalt or ground paved with wood. Similarly, it does not become pure by rubbing it against or drawing it along a wall.

-Ayatullah Sistani, Practical Laws of Islam, Purification (Taharah)