Hadith 3228 - Beginning of Creation - Sahih Al-Bukhari - صحيح البخاري - Collection of Actions, Sayings and Teachings of Prophet Muhammad (صلى الله عليه و سلم) - Kutub as-Sittah

59. Beginning of Creation - كتاب بدء الخلق

7) Chapter: If anyone says Amin [during the Salat (prayer) at the end of the recitation of Surat Al-Fatiha]

Narrated Abu Huraira:

Allah's Messenger (ﷺ) said, "When the Imam, during the prayer, says, "Allah hears him who praises Him', say: 'O Allah! Our Lord! All the praises are for You/, for if the saying of anyone of you coincides with the saying of the angels, his past sins will be forgiven."

Reference: 3228
English reference: Vol. 4, Book 54, Hadith 451
In-book reference: Book 59, Hadith 39
Grade: Sahih
Read this hadith from Darussalam Collection

7) بَابُ إِذَا قَالَ أَحَدُكُمْ آمِينَ. وَالْمَلاَئِكَةُ فِي السَّمَاءِ، فَوَافَقَتْ إِحْدَاهُمَا الأُخْرَى، غُفِرَ لَهُ مَا تَقَدَّمَ مِنْ ذَنْبِهِ

حَدَّثَنَا إِسْمَاعِيلُ، قَالَ حَدَّثَنِي مَالِكٌ، عَنْ سُمَىٍّ، عَنْ أَبِي صَالِحٍ، عَنْ أَبِي هُرَيْرَةَ ـ رضى الله عنه ـ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ ‏‏‏.‏ "‏ إِذَا قَالَ الإِمَامُ سَمِعَ اللَّهُ لِمَنْ حَمِدَهُ‏.‏ فَقُولُوا اللَّهُمَّ رَبَّنَا لَكَ الْحَمْدُ، فَإِنَّهُ مَنْ وَافَقَ قَوْلُهُ قَوْلَ الْمَلاَئِكَةِ، غُفِرَ لَهُ مَا تَقَدَّمَ مِنْ ذَنْبِهِ ‏"