From Sahih Muslim (Hadith 1165):
Hudhaifa reported:The Messenger of Allah (may peace be npon him) said: We have been made to excel (other) people in three (things): Our rows have been made like the rows of the angels and the whole earth has been made a mosque for us, and its dust has been made a purifier for us in case water is not available. And he mentioned another characteristic too
Reference: Muslim 1165