Al-Kāfi - Volume 6 > The Case of the Tails of Sheep Cut off into two and the Animal Hunted
Hadith #3

الْحُسَيْنُ بْنُ مُحَمَّدٍ عَنْ مُعَلَّى بْنِ مُحَمَّدٍ عَنِ الْحَسَنِ بْنِ عَلِيٍّ قَالَ سَأَلْتُ أَبَا الْحَسَنِ ( عليه السلام ) فَقُلْتُ لَهُ جُعِلْتُ فِدَاكَ إِنَّ أَهْلَ الْجَبَلِ تَثْقُلُ عِنْدَهُمْ أَلَيَاتُ الْغَنَمِ فَيَقْطَعُونَهَا فَقَالَ حَرَامٌ هِيَ فَقُلْتُ جُعِلْتُ فِدَاكَ فَنَصْطَبِحُ بِهَا فَقَالَ أَ مَا عَلِمْتَ أَنَّهُ يُصِيبُ الْيَدَ وَ الثَّوْبَ وَ هُوَ حَرَامٌ .

3. Al-Husayn from Muhammad has narrated from Mu‘alla’ ibn Muhammad from al-Hassan ibn Ali who has said the following: “I once asked abu al-Hassan, ‘Alayhi al-Salam, saying, ‘I pray to Allah to keep my soul in service for your cause, people who live in the mountains cut off the tails of their sheep because they become very large.’ He (the Imam) said, ‘It is not lawful (inedible).’ I then asked, saying, ‘I pray to Allah to keep my soul in service for your cause, can it be used in lamps for lighting during the night? He (the Imam) said, ‘You must take notice that it can come in contact with your hand and clothes and it is unlawful.’”