Musannaf Ibn Abi Shayba 16:535

Abu Bakr narrated to us, he said: Yazid bin Harun narrated to us, he said: Ibn 'Awn informed us, from Mujahid, who said: Ibn Umar saw a man wearing a *farwa* (a fur garment), and its softness pleased him. He said: "If I knew this was pure/intelligent, it would please me to have a garment made from it."