Sahih Bukhari
Rubbing hands and feet with dust (Tayammum)
Volume: 001 / Book Number: 007 / Hadith Number: 333
Narrated Abu Juhaim Al-Ansari:
The Prophet came from the direction of Bir Jamal. A man met him and greeted him. But he did not return back the greeting till he went to a (mud) wall and smeared his hands and his face with its dust (performed Tayammum) and then returned back the greeting.