Chapter on the Reward of Fasting in Rajab
Man Lā Yaḥḍuruh al-Faqīh|Volume 2|Book 2|Chapter 6
وَ قَالَ أَبُو اَلْحَسَنِ مُوسَى بْنُ جَعْفَرٍ عَلَيْهِمَا اَلسَّلاَمُ: « رَجَبٌ شَهْرٌ عَظِيمٌ يُضَاعِفُ اَللَّهُ فِيهِ اَلْحَسَنَاتِ وَ يَمْحُو فِيهِ اَلسَّيِّئَاتِ مَنْ صَامَ يَوْماً مِنْ رَجَبٍ تَبَاعَدَتْ عَنْهُ اَلنَّارُ مَسِيرَةَ سَنَةٍ وَ مَنْ صَامَ ثَلاَثَةَ أَيَّامٍ وَجَبَتْ لَهُ اَلْجَنَّةُ ».
Abu al-Hasan Imam Musa ibn Jafar Al-Kadhim عليه السلام said: "Rajab is a great month. In it, Allah سبحانه وتعالى multiplies good deeds and erases sins. Whoever fasts a day in Rajab, the Fire will be distanced from him by a journey of one year, and whoever fasts three days, Paradise becomes obligatory for him."
- Ṣaḥīḥ al-Faqīh