Prayer at the Mosque of Ghadir Khumm
Man Lā Yaḥḍuruh al-Faqīh|Volume 2|Book 3|Chapter 152
فَإِنَّ أَحْمَدَ بْنَ مُحَمَّدِ بْنِ أَبِي نَصْرٍ رَوَى عَنْ أَبَانٍ عَنْ أَبِي عَبْدِ اَللَّهِ عَلَيْهِ اَلسَّلاَمُ أَنَّهُ قَالَ: «يُسْتَحَبُّ اَلصَّلاَةُ فِي مَسْجِدِ اَلْغَدِيرِ لِأَنَّ اَلنَّبِيَّ صَلَّى اَللَّهُ عَلَيْهِ وَ آلِهِ أَقَامَ فِيهِ أَمِيرَ اَلْمُؤْمِنِينَ عَلَيْهِ اَلسَّلاَمُ وَ هُوَ مَوْضِعٌ أَظْهَرَ اَللَّهُ فِيهِ اَلْحَقَّ».
It is narrated from Ahmad ibn Muhammad ibn Abi Nasr, from Aban, from Abu Abdullah عليه السلام, that he said: "Praying in the Mosque of Ghadir is recommended because the Prophet (peace be upon him and his family) appointed the Commander of the Faithful عليه السلام there, and it is a place where Allah سبحانه وتعالى manifested the truth."
- Ṣaḥīḥ al-Faqīh, p. 180