Purity: Purity of Body Parts in Tayammum

Practical Laws of Islam as per the teachings of Ayatullah Sistani

Ruling 695:

In tayammum it is not necessary for one’s forehead, the palms of his hands, and the back of his hands to be pure. Therefore, if the parts of the body on which tayammum is performed have become impure but are dry, the tayammum is valid, although it is better that the parts of the body on which tayammum is performed be completely pure.

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