Congregational Prayer and Its Virtue
Man Lā Yaḥḍuruh al-Faqīh|Volume 1|Book 1|Chapter 57
وَقَالَ اَلصَّادِقُ عَلَيْهِ اَلسَّلاَمُ: «إِذَا صَلَّيْتَ مَعَهُمْ غُفِرَ لَكَ بِعَدَدِ مَنْ خَالَفَكَ.
Imam Jafar ibn Muhammad Al-Sadiq عليه السلام said: "If you pray with them, you will be forgiven to the extent of the number of those who oppose you."
- Ṣaḥīḥ al-Faqīh, p. 59