Congregational Prayer and Its Virtue
Man Lā Yaḥḍuruh al-Faqīh|Volume 1|Book 1|Chapter 57
وَ فِي كِتَابِ زِيَادِ بْنِ مَرْوَانَ اَلْقَنْدِيِّ وَ فِي نَوَادِرِ مُحَمَّدِ بْنِ أَبِي عُمَيْرٍ أَنَّ اَلصَّادِقَ عَلَيْهِ اَلسَّلاَمُ قَالَ: فِي رَجُلٍ صَلَّى بِقَوْمٍ مِنْ حِينَ خَرَجُوا مِنْ خُرَاسَانَ حَتَّى قَدِمُوا مَكَّةَ فَإِذَا هُوَ يَهُودِيٌّ أَوْ نَصْرَانِيٌّ قَالَ «لَيْسَ عَلَيْهِمْ إِعَادَةٌ.
In the book of Ziyad ibn Marwan al-Qandi and in the Nawadir of Muhammad ibn Abi Umayr, it is narrated that Imam Jafar ibn Muhammad Al-Sadiq عليه السلام said regarding a man who led a group in prayer from the time they left Khurasan until they reached Mecca, and then it was discovered that he was a Jew or a Christian: "They do not need to repeat their prayers”.
- Ṣaḥīḥ al-Faqīh