Language:
كتاب بدء الخلق
59
Beginning of Creation
(7)
Chapter: If anyone says Amin [during the Salat (prayer) at the end of the recitation of Surat Al-Fatiha]
(7)
بَابُ إِذَا قَالَ أَحَدُكُمْ آمِينَ. وَالْمَلاَئِكَةُ فِي السَّمَاءِ، فَوَافَقَتْ إِحْدَاهُمَا الأُخْرَى، غُفِرَ لَهُ مَا تَقَدَّمَ مِنْ ذَنْبِهِ

Narrated Jabir bin `Abdullah:

that he heard the Prophet (ﷺ) saying, "The Divine Inspiration was delayed for a short period but suddenly, as I was walking. I heard a voice in the sky, and when I looked up towards the sky, to my surprise, I saw the angel who had come to me in the Hira Cave, and he was sitting on a chair in between the sky and the earth. I was so frightened by him that I fell on the ground and came to my family and said (to them), 'Cover me! (with a blanket), cover me!' Then Allah sent the Revelation: "O, You wrapped up (In a blanket)! (Arise and warn! And your Lord magnify And keep pure your garments, And desert the idols." (74.1-5)

حَدَّثَنَا عَبْدُ اللَّهِ بْنُ يُوسُفَ، أَخْبَرَنَا اللَّيْثُ، قَالَ حَدَّثَنِي عُقَيْلٌ، عَنِ ابْنِ شِهَابٍ، قَالَ سَمِعْتُ أَبَا سَلَمَةَ، قَالَ أَخْبَرَنِي جَابِرُ بْنُ عَبْدِ اللَّهِ ـ رضى الله عنهما ـ أَنَّهُ سَمِعَ النَّبِيَّ صلى الله عليه وسلم يَقُولُ ‏"‏ ثُمَّ فَتَرَ عَنِّي الْوَحْىُ فَتْرَةً، فَبَيْنَا أَنَا أَمْشِي سَمِعْتُ صَوْتًا مِنَ السَّمَاءِ، فَرَفَعْتُ بَصَرِي قِبَلَ السَّمَاءِ فَإِذَا الْمَلَكُ الَّذِي جَاءَنِي بِحِرَاءٍ قَاعِدٌ عَلَى كُرْسِيٍّ بَيْنَ السَّمَاءِ وَالأَرْضِ، فَجُئِثْتُ مِنْهُ حَتَّى هَوَيْتُ إِلَى الأَرْضِ، فَجِئْتُ أَهْلِي فَقُلْتُ زَمِّلُونِي زَمِّلُونِي‏.‏ فَأَنْزَلَ اللَّهُ تَعَالَى ‏{‏يَا أَيُّهَا الْمُدَّثِّرُ‏}‏ إِلَى ‏{‏فَاهْجُرْ‏}‏ ‏"‏‏.‏ قَالَ أَبُو سَلَمَةَ وَالرِّجْزُ الأَوْثَانُ‏.‏
Reference : Sahih al-Bukhari 3238
In-book reference : Book 59, Hadith 49
USC-MSA web (English) reference : Vol. 4, Book 54, Hadith 461
  (deprecated numbering scheme)