Abu Dawud Book 27, Hadith Number 4114.
Chapter : Skins of dead animals.
Narated By Maymunah : Al-Aliyah, daughter of Subay’, said: I had some sheep at Uhud, and they began to die. I then entered upon Maymunah, wife of the Prophet (PBUH), and mentioned it to her. Maymunah said to me: If you took their skins and made use of them, (that would be better for you). She asked: Is that lawful? She replied, Yes. Some people of the Quraysh passed by the Apostle of Allah (PBUH) dragging a sheep of theirs as big as an ass. The Apostle of Allah (PBUH) said to them: Would that you took its skin. They said: It died a natural death. The Apostle of Allah (PBUH) said: Water and leaves of the mimosa flava purify it.