Al-Kāfi - Volume 5 > Unlawful Earnings in the form of al-Suht such as Buying and Selling of Intoxicating Liquors . . .
Hadith #4

4- مُحَمَّدُ بْنُ يَحْيَى عَنْ أَحْمَدَ بْنِ مُحَمَّدٍ عَنْ مُحَمَّدِ بْنِ سِنَانٍ عَنِ ابْنِ مُسْكَانَ عَنْ يَزِيدَ بْنِ فَرْقَدٍ عَنْ أَبِي عَبْدِ اللهِ (عَلَيْهِ السَّلام) قَالَ سَأَلْتُهُ عَنِ السُّحْتِ فَقَالَ الرِّشَا فِي الْحُكْمِ.

4. Muhammad ibn Yahya has narrated from Ahmad ibn Muhammad from Muhammad ibn Sinan from ibn Muskan from Yazid ibn Farqad who has said the following: “This is concerning my question before abu ‘Abd Allah, ‘Alayhi al-Salam, about Suht (unlawful and filthy). He (the Imam) said, ‘It is accepting a bribe to issue a judgment.’”