Sayyiduna Bara’ (may Allah be pleased with him) narrates: A man was reciting Surah Al-Kahf. His animal was tied nearby. The animal began to jump. The man saw a cloud that had covered him. That man went to the service of the Prophet (peace and blessings of Allah be upon him) and mentioned this matter to him. The Prophet (peace and blessings of Allah be upon him) said: “O so-and-so! Continue reciting, that was tranquility which was descending because of the Qur’an (the narrator is in doubt, perhaps these are the words:) because of the Qur’an.”
Hadith Referenceصحیح ابن حبان / كتاب الرقائق / 769
Hadith Gradingفضيلة الشيخ الإمام محمد ناصر الدين الألبانيصحيح - «صحيح سنن الترمذي» (3058): ق.فضيلة الشيخ العلّامة شُعيب الأرناؤوطإسناده صحيح على شرط الشيخين.