Congregational Prayer and Its Virtue
Man Lā Yaḥḍuruh al-Faqīh|Volume 1|Book 1|Chapter 57
وَ رَوَى اَلْحَلَبِيُّ عَنْ أَبِي عَبْدِ اَللَّهِ عَلَيْهِ اَلسَّلاَمُ أَنَّهُ قَالَ: «إِذَا فَاتَكَ شَيْءٌ مَعَ اَلْإِمَامِ فَاجْعَلْ أَوَّلَ صَلاَتِكَ مَا اِسْتَقْبَلْتَ مِنْهَا وَ لاَ تَجْعَلْ أَوَّلَ صَلاَتِكَ آخِرَهَا.
Al-Halabi narrated from Imam Jafar ibn Muhammad Al-Sadiq عليه السلام that He said: "If you miss a part of the prayer with the Imam, consider what you perform upon joining as the beginning of your prayer, and do not consider the beginning of your prayer as its end”.
- Ṣaḥīḥ al-Faqīh