Full Sharh — Mishkat al-Masabih 472
وَعَن مَيْمُونَة مر على النَّبِي الله صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ رِجَالٌ مِنْ قُرَيْشٍ يَجُرُّونَ شَاةً لَهُمْ مِثْلَ الْحِمَارِ فَقَالَ لَهُمْ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «لَوْ أَخَذْتُمْ إِهَابَهَا» قَالُوا إِنَّهَا مَيْتَةٌ فَقَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «يُطَهِّرُهَا الْمَاءُ والقرظ» . رَوَاهُ أَحْمد وَأَبُو دَاوُد
English Translation
Maimuna said that some people passed the Prophet dragging a sheep of theirs as big as an ass. God’s messenger asked them why they did not make use of its skin, and when they told him that it had died a natural death he said, “Water and leaves of the mimosa flava* purify it." *The Arabic word is qaraz. meaning the leaves of the mimosa flave (salam) These were used for tanning. Ahmad and Abu Dawud transmitted it.
Source
Mishkat al-Masabih(مشكاة المصابيح)
Purification
Hadith Number
472