[Machine] About the Prophet ﷺ regarding the skins of dead animals, it is said that their tanning process removes their impurities or filth.  

عَنِ النَّبِيِّ ﷺ فِي جُلُودِ الْمَيْتَةِ أَنَّ دِبَاغَهَا قَدْ ذَهَبَ بِخَبَثِهِ أَوْ بِنَجَسِهِ أَوْ رِجْسِهِ  

[Machine] From a man among the companions of the Prophet ﷺ from the Ansar, he informed him that the Messenger of Allah ﷺ prohibited anyone from using the bones, dung, or animal skin for fragrance. Abu Bakr al-Harifi informed us of this. I am Ali ibn Umar al-Hafidh and Ja'far ibn Muhammad ibn Nasir narrated to me, from Al-Hasan ibn Ali, from Abu Tahir and Amr ibn Suwaid, they said: Ibn Wahb narrated from Umar ibn al-Harith, and he mentioned it. Ali ibn Umar said, "This chain is not reliable."  

عَنْ رَجُلٍ مِنْ أَصْحَابِ النَّبِيِّ ﷺ مِنَ الْأَنْصَارِ أَخْبَرَهُ عَنْ رَسُولِ اللهِ ﷺ أَنَّهُ نَهَى أَنْ يَسْتَطِيبَ أَحَدٌ بِعَظْمٍ أَوْ رَوْثَةٍ أَوْ جِلْدٍ فَقَدْ أَخْبَرَنَاهُ أَبُو بَكْرٍ الْحَارِثِيُّ أَنَا عَلِيُّ بْنُ عُمَرَ الْحَافِظُ حَدَّثَنِي جَعْفَرُ بْنُ مُحَمَّدِ بْنِ نُصَيْرٍ ثنا الْحَسَنُ بْنُ عَلِيٍّ ثنا أَبُو طَاهِرِ وَعَمْرُو بْنُ سَوَّادٍ قَالَا نا ابْنُ وَهْبٍ عَنْ عُمَرِو بْنِ الْحَارِثِ فَذَكَرَهُ قَالَ عَلِيُّ بْنُ عُمَرَ هَذَا إِسْنَادٌ غَيْرُ ثَابِتٍ