Narrated 'Abdullah bin 'Ukaim:
A letter came from the Messenger of Allah (ﷺ) saying: 'Do not use the skins of dead animals, nor tendons.'
[Abu 'Eisa said:] This Hadith is Hasan. This Hadith has been related to 'Abdullah bin 'Ukaim from some Shuyukh of his, and this is not acted upon according to most of the people of knowledge. And this Hadith has been related from 'Abdullah bin 'Ukaim, that he said: A letter came to us from the Messenger of Allah (ﷺ) two months before he died.
He said: I heart Ahmad bin Al-Hasan saying: Ahmad bin Hanbal followed this Hadith due to it mentioning that it was two months before he (ﷺ) died. Then Ahmad left this Hadith because of their Idtirab in its chain, since some of them reported it, saying: 'From 'Abdullah bin 'Ukaim from some Shuyukh of his from Juhainah.'