Sahih al-Bukhari
Book 66: Virtues of the Qur'an
كتاب فضائل القرآن
87 hadith in this book
Narrated Al-Bara':
A man was reciting Surat Al-Kahf and his horse was tied with two ropes beside him. A cloud came down and spread over that man, and it kept on coming closer and closer to him till his horse started jumping (as if afraid of something). When it was morning, the man came to the Prophet, and told him of that experience. The Prophet (ﷺ) said, "That was As-Sakina (tranquility) which descended because of (the recitation of) the Qur'an."
حَدَّثَنَا عَمْرُو بْنُ خَالِدٍ، حَدَّثَنَا زُهَيْرٌ، حَدَّثَنَا أَبُو إِسْحَاقَ، عَنِ الْبَرَاءِ، قَالَ كَانَ رَجُلٌ يَقْرَأُ سُورَةَ الْكَهْفِ وَإِلَى جَانِبِهِ حِصَانٌ مَرْبُوطٌ بِشَطَنَيْنِ فَتَغَشَّتْهُ سَحَابَةٌ فَجَعَلَتْ تَدْنُو وَتَدْنُو وَجَعَلَ فَرَسُهُ يَنْفِرُ فَلَمَّا أَصْبَحَ أَتَى النَّبِيَّ صلى الله عليه وسلم فَذَكَرَ ذَلِكَ لَهُ فَقَالَ " تِلْكَ السَّكِينَةُ تَنَزَّلَتْ بِالْقُرْآنِ ".
Hadith text, translations and grading are courtesy of Sunnah.com.