Purity: Wiping Over Socks or Shoes
Practical Laws of Islam as per the teachings of Ayatullah Sistani
Ruling 258
Wiping performed on socks or shoes is invalid. However, if one is unable to remove his socks or shoes on account of severe cold, or fear of thieves or predatory animals etc., then the obligatory precaution is that after he has wiped on his shoes or socks, he must also perform tayammum. If it is a matter of taqiyyah,[1] it is sufficient if he only wipes over his socks or shoes.
-Ayatullah Sistani, Practical Laws of Islam, Purification (Taharah)
1
Taqiyyah refers to dissimulation or concealment of one’s beliefs in the face of danger.