It was narrated that Abu Hurairah said:
It was said: "O Messenger of Allah, we want to come to the mosque, but the path that we walk upon is impure." The Messenger of Allah said: "Some parts of the earth purify others." (RU)
English reference (RU): Vol. 1, Book 1, Hadith 532 (RU)
Arabic reference (RU): Book 1, Hadith 575 (RU)