Musannaf Ibn Abi Shayba 16:1047

Abu Bakr narrated to us, he said: Ali ibn Mushir narrated to us, from al-Shaybani, from al-Hakam, from Abd al-Rahman ibn Abi Layla, from Abdullah ibn Ukaym, who said: The letter of the Prophet, may Allah bless him and grant him peace, came to us while we were among the Juhayna: "Do not benefit from the dead animal, neither from its skin nor its sinew."