Al-Kāfi

Hadith 1218
food-drink
عَلِيُّ بْنُ إِبْرَاهِيمَ عَنْ أَبِيهِ عَنْ أَحْمَدَ بْنِ مُحَمَّدِ بْنِ أَبِي نَصْرٍ عَنْ حَمَّادِ بْنِ عُثْمَانَ عَنْ مُحَمَّدِ بْنِ سُوقَةَ عَنْ أَبِي عَبْدِ اللَّهِ ( عليه السلام ) قَالَ مَنْ أَكَلَ لُقْمَةَ شَحْمٍ أَخْرَجَتْ مِثْلَهَا مِنَ الدَّاءِ .
5. Ali ibn Ibrahim has narrated from his father from Ahmad ibn Muhammad from ibn abu Nasr from Hammad ibn ‘Uthaman from Muhammad ibn Sawqah who has said the following: “Abu ‘Abd Allah (a.s.), has said, ‘If one eats a morsel of shahm (fat) it expels the same amount of illness out.’”
Source: Shaykh Muḥammad b. Yaʿqūb al-Kulaynī