793. hadíth
وَ رُوِيَ عَنْ جَعْفَرِ بْنِ مُحَمَّدِ بْنِ يُونُسَ أَنَّ أَبَاهُ كَتَبَ إِلَى أَبِي اَلْحَسَنِ عَلَيْهِ اَلسَّلاَمُ: يَسْأَلُهُ عَنِ اَلْفَرْوِ وَ اَلْخُفِّ أَلْبَسُهُ وَ أُصَلِّي فِيهِ وَ لاَ أَعْلَمُ أَنَّهُ ذَكِيٌّ فَكَتَبَ «لاَ بَأْسَ بِهِ.
It was narrated from Ja'far ibn Muhammad ibn Yunus that his father wrote to Imam Abu Al-Hasan (a.s) asking about wearing fur or leather socks (khuff) and praying in them without knowing if they were from a properly slaughtered (halal) animal. He (a.s) replied: "There is no harm in it”.