Chapter on Virtues of Hajj
Man Lā Yaḥḍuruh al-Faqīh|Volume 2|Book 3|Chapter 2
وَ قَالَ اَلرِّضَا عَلَيْهِ اَلسَّلاَمُ: « لَيْلَةُ خَمْسَةٍ وَ عِشْرِينَ مِنْ ذِي اَلْقَعْدَةِ دُحِيَتِ اَلْأَرْضُ مِنْ تَحْتِ اَلْكَعْبَةِ فَمَنْ صَامَ ذَلِكَ اَلْيَوْمَ كَانَ كَمَنْ صَامَ سِتِّينَ شَهْراً ».
Imam Ali ibn Musa Ar-Ridha عليه السلام said: "On the night of the 25th of Dhu al-Qa'dah, the earth was spread out from beneath the Kaaba. Whoever fasts on that day, it is as if they have fasted for sixty months."
- Ṣaḥīḥ al-Faqīh