Congregational Prayer and Its Virtue
Man Lā Yaḥḍuruh al-Faqīh|Volume 1|Book 1|Chapter 57
وَ رُوِيَ عَنْ إِسْمَاعِيلَ بْنِ مُسْلِمٍ أَنَّهُ سَأَلَ اَلصَّادِقَ عَلَيْهِ اَلسَّلاَمُ: عَنِ اَلصَّلاَةِ خَلْفَ رَجُلٍ يُكَذِّبُ بِقَدَرِ اَللَّهِ عَزَّ وَ جَلَّ قَالَ «لِيُعِدْ كُلَّ صَلاَةٍ صَلاَّهَا خَلْفَهُ.
It was narrated from Isma'il ibn Muslim that he asked Imam Jafar ibn Muhammad Al-Sadiq عليه السلام about praying behind a man who denies (or rejects) the decree (Qadar) of Allah سبحانه وتعالى, the Mighty and Majestic. He (Al-Sadiq) replied: "He should repeat every prayer he performed behind him”.
- Ṣaḥīḥ al-Faqīh, p. 53