Abu Dawud Book 1, Hadith Number 384.
Chapter : On the border of the clothe smeared with impurity.
Narated By A woman of the Banu Abdul Ashhal : She reported: I said Apostle of Allah, our road to the mosque has an unpleasant stench; what should we do when it is raining? He asked: Is there not a cleaner part after the filthy part of the road? She replied: Why not (there is one)! He said: It makes up for the other.