Musnad Abu Ya'la al-Mawsili 106:69

And through him, from Abu Ishaq, who said: I heard al-Bara’ say: A man recited [Surah] al-Kahf, and in the house there was a beast, and it began to shy away. He gave the greeting (salam), and behold, a mist or a cloud had covered him. He mentioned that to the Prophet, may Allah bless him and grant him peace, and he said: "Recite, so-and-so, for it is the tranquility (al-sakinah) that descended at the [time of] the Quran," or he said: "descended for the Quran."