Al-Kāfi - Volume 4

Excellence of Fasting in the Month of Shaman, Continuing Such Fast to Connect it with the Month of Ramadan, and Three Days of Fasting Every Month

12ـ عَلِيُّ بْنُ إِبْرَاهِيمَ عَنْ مُحَمَّدِ بْنِ عِيسَى بْنِ عُبَيْدٍ عَنْ يُونُسَ عَنْ إِسْحَاقَ بْنِ عَمَّارٍ عَنْ أَبِي عَبْدِ الله (عَلَيْهِ السَّلاَم) قَالَ قَالَ إِنَّمَا يُصَامُ يَوْمُ الأَرْبِعَاءِ لأَنَّهُ لَمْ تُعَذَّبْ أُمَّةٌ فِيمَا مَضَى إِلاَّ فِي يَوْمِ الأَرْبِعَاءِ وَسَطِ الشَّهْرِ فَيُسْتَحَبُّ أَنْ يُصَامَ ذَلِكَ الْيَوْمُ.

12. Ali ibn Ibrahim has narrated from Muhammad ibn ‘Isa ibn ‘Ubayd from Yunus from Ishaq ibn ‘Ammar who has said the following: “Abu ‘Abd Allah (a.s.), has said that there is fasting on Wednesday because for all nations upon which torment descended, it occurred on a Wednesday in the middle of the month. It is desirable to fast on that day.” 

Al-Kāfi - Volume 4

Book 2, Chapter #13