(a) Some people came to Sayyiduna Abdullah bin Ukaym (may Allah be pleased with him), and he told them that the Messenger of Allah (peace and blessings be upon him) wrote to the people of the tribe of Juhaynah one month before his death: "Do not benefit from the skin of a dead animal, nor from its sinews."
(b) Imam al-Bayhaqi (may Allah have mercy on him) said: This hadith has also come through another chain, whose wording is that he (peace and blessings be upon him) wrote this letter forty days before his death. It is narrated from Sayyiduna Abdullah bin Ukaym (may Allah be pleased with him): The elders of our tribe Juhaynah told us that the Prophet (peace and blessings be upon him) wrote to them. This will be mentioned later, if Allah wills.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 43