And as for what was narrated by Al-Husayn ibn Sa‘id, from Jamil ibn Darraj, from Abu Abdillah عليه السلام, who said:
I asked Him عليه السلام about prayer in the skins of foxes. Imam عليه السلام said: "If they are from a properly slaughtered animal (dhakiyyah), then there is no problem."
Ali Akbar al-Ghaffari
Tahdhīb al-Aḥkām fī Sharḥ al-Muqniʿah, vol. 2, p. 219