Congregational Prayer and Its Virtue
Man Lā Yaḥḍuruh al-Faqīh|Volume 1|Book 1|Chapter 57
وَ سَأَلَ عَلِيُّ بْنُ جَعْفَرٍ عَلَيْهِ اَلسَّلاَمُ أَخَاهُ مُوسَى بْنَ جَعْفَرٍ عَلَيْهِمَا اَلسَّلاَمُ: عَنْ إِمَامٍ أَحْدَثَ وَ اِنْصَرَفَ وَ لَمْ يُقَدِّمْ أَحَداً مَا حَالُ اَلْقَوْمِ قَالَ «لاَ صَلاَةَ لَهُمْ إِلاَّ بِإِمَامٍ فَلْيُقَدِّمْ بَعْضُهُمْ بَعْضَهُمْ فَلْيُتِمَّ بِهِمْ مَا بَقِيَ مِنْهَا وَ قَدْ تَمَّتْ صَلاَتُهُمْ.
Ali ibn Ja'far asked his brother Imam Musa ibn Jafar Al-Kadhim عليه السلام about an Imam who becomes impure (invalidates his wudu') and leaves the prayer without appointing someone to continue leading. What is the status of the congregation? Imam عليه السلام replied: "There is no valid prayer for them without an Imam. Therefore, one of them should step forward to lead the remainder of the prayer, and their prayer will be completed."
- Ṣaḥīḥ al-Faqīh