Congregational Prayer and Its Virtue
Man Lā Yaḥḍuruh al-Faqīh|Volume 1|Book 1|Chapter 57
وَقَالَ أَبُو جَعْفَرٍ عَلَيْهِ اَلسَّلاَمُ: «إِنَّمَا اَلْأَعْمَى أَعْمَى اَلْقَلْبِ فَإِنَّهَا «لاٰ تَعْمَى اَلْأَبْصٰارُ وَ لٰكِنْ تَعْمَى اَلْقُلُوبُ اَلَّتِي فِي اَلصُّدُورِ» »
Imam Muhammad ibn Ali Al-Baqir عليه السلام said: "Indeed, the truly blind are those who are blind in their hearts, for it is not the eyes that go blind but the hearts within the chests."
- Ṣaḥīḥ al-Faqīh