A man was reciting Surah al-Kahf, and in the house there was an animal that began to grow restless. He gave the salam to end his prayer, and behold, a mist or cloud had overshadowed him. He mentioned this to the Prophet ﷺ, who said, "Recite, so-and-so, for that was tranquility that descended for the Quran," or "came down for the Quran."
حدثني محمد بن بشار حدثنا غندر حدثنا شعبة عن أبي إسحاق سمعت
قرأ رجل الكهف وفي الدار الدابة فجعلت تنفر فسلم فإذا ضبابة أو سحابة غشيته فذكره للنبي ﷺ فقال اقرأ فلان فإنها السكينة نزلت للقرآن أو تنزلت للقرآن