Al-Kāfi

Hadith 1696
duacongregational-prayer
4ـ عَلِيُّ بْنُ إِبْرَاهِيمَ عَنْ أَبِيهِ عَنِ النَّوْفَلِيِّ عَنِ السَّكُونِيِّ عَنْ أَبِي عَبْدِ الله (عَلَيهِ السَّلام) قَالَ الدَّاعِي وَالْمُؤَمِّنُ فِي الأجْرِ شَرِيكَانِ.
4. Ali ibn Ibrahim has narrated from his father from al-Nawfali from al-Sakuni from Abu ‘Abdillah (a.s.) who has said the following: “Abu ‘Abd Allah (a.s.) has said, ‘A person praying and one saying ‘Amin’ share the reward equally.’”
Source: Shaykh Muḥammad b. Yaʿqūb al-Kulaynī