“There came to us a letter from the Prophet ﷺ (saying): ‘No not make use of the untanned skin and sinew of dead animals.’” (Using translation from Ibn Mājah 3613)
كَتَبَ إِلَيْنَا رَسُولُ اللهِ ﷺ «أَنْ لَا تَسْتَنْفِعُوا مِنَ الْمَيْتَةِ بِإِهَابٍ وَلَا عَصْبٍ»