The Book of al-Fara' and al-'Atirah
41/4. Chapter:
The Skin Of Dead Animals (Those Not Slaughtered Or Killed Properly)
Sunan an-Nasai
أَخْبَرَنَا الْحُسَيْنُ بْنُ مَنْصُورِ بْنِ جَعْفَرٍ النَّيْسَابُورِيُّ، قَالَ حَدَّثَنَا الْحُسَيْنُ بْنُ مُحَمَّدٍ، قَالَ حَدَّثَنَا شَرِيكٌ، عَنِ الأَعْمَشِ، عَنْ عُمَارَةَ بْنِ عُمَيْرٍ، عَنِ الأَسْوَدِ، عَنْ عَائِشَةَ، قَالَتْ سُئِلَ النَّبِيُّ صلى الله عليه وسلم عَنْ جُلُودِ الْمَيْتَةِ فَقَالَ " دِبَاغُهَا طَهُورُهَا " .
It was narrated that 'Aishah said: "The Prophet was asked about the hides of dead animals." He said: "Tanning it purifies it."
Reference : Sunan an-Nasa'i 4244In-book reference : Book 41, Hadith 23English translation : Vol. 5, Book 41, Hadith 4249