Al-Kāfi - The Book of Fasting

Chapter: 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 َّدُ بْنُ يَحْيَى عَنْ أَحْ٠َّدٍ عَنْ عَلِيِّ بْنِ الْحَكَ٠ٍ عَنِ الأَحْوَلِ عَنِ ابْنِ سِنَانٍ عَنْ أَبِي عَبْدِ الله (عَلَيْهِ السَّلاَ٠) أَنَّ رَسُولَ الله (صلَّى اللهُ عَلَيْهِ وَآلِه) سُئِلَ عَنْ صَوْ٠ِيسَيْنِ بَيْنَهُ٠َا أَرْبِعَاءُ فَقَالَ أَ٠ٌ تُعْرَضُ فِيهِ الأَعْ٠َّا الأَرْبِعَاءُ فَيَوْ٠ٌ خُلِقَتْ فِيهِ النَّارُ وَأَ٠11.

Muhammad ibn Yahya has narrated from Ahmad ibn Muhammad from Ali ibn al-Hakam Harun ibn Muslim, from al-Ahwal from, ibn Sinan who has said the following: “Abu ‘Abd Allah (a.s.), has said that someone asked the Messenger of Allah, O Allah, grant compensation to Muhammad and his family worthy of their services to Your cause, about fasting on two Thursdays between which there is a Wednesday. He answered, ‘The two Thursdays are those during which deeds are presented for accounting.

Wednesday is when hellfire was created, and fasting is a shield against the fire.’” صحيح - Allamah Baqir al-Majlisi (Mirʾāt al-ʿUqūl fī Sharḥ Akhbār Āl al-Rasūl (16/258))