While a man from the companions of the Prophet was reciting (Quran) and his horse was tied in the house, the horse got startled and started jumping. The man came out, looked around but could not find anything, yet the horse went on jumping. The next morning he mentioned that to the Prophet. The Prophet ﷺ said, "That was the tranquility (calmness) which descended because of the recitation of the Quran."
Sahih al-Bukhari, Vol. 6, Book of Prophetic Commentary on the Qur'an, Hadith 363
Sahih al-Bukhari, Book of Prophetic Commentary on the Qur'an, Hadith 363