The Messenger of Allah ﷺ was the most handsome of people, the most generous of people, and the bravest of people. One night, the people of Medina were alarmed by a sound, and some men set out toward it. The Messenger of Allah ﷺ met them on his way back, having reached the source of the sound before them. He was riding a horse belonging to Abu Talha, bareback, with a sword slung around his neck, saying, "Do not be afraid, do not be afraid."He said, "We found him to be like a sea," or, "Indeed, he is a sea."The horse had previously been known to be slow.
كان رسول الله ﷺ أحسن الناس، وكان أجود الناس، وكان أشجع الناس، ولقد فزع أهل المدينة ذات ليلة فانطلق ناس قبل الصوت، فتلقاهم رسول الله ﷺ راجعا، وقد سبقهم إلى الصوت، وهو على فرس لأبي طلحة عري، في عنقه السيف، وهو يقول: لم تراعوا، لم تراعوا، قال: وجدناه بحرا، أو إنه لبحر، قال وكان فرسا يبطأ.
Bukhari related it in jihad (2908), and Muslim in virtues (2307:48), both through routes going back to Hammad bin Zayd, from Thabit, from Anas, who said, and then he narrated it. The wording given is Muslim's.Bukhari also related it in jihad (2862), and Muslim in virtues (2307:49), through routes going back to Shubah, from Qatada, from Anas, who said, there was alarm in Madinah, so the Prophet ﷺ borrowed a horse from Abu Talha called Mandub. He rode it and said, "We saw nothing to be alarmed about, and we found it to be as fast as the sea."His saying, "Do not be alarmed," is in the passive form, derived from rawh, meaning fright. Abu Talha's horse was slow, but after the Prophet ﷺ rode it, it became capable of running at great speed. Ibn Majah (2772) mentioned, following the hadith just cited, that Hammad (that is, Ibn Zayd) said, Thabit and others told me, saying, "It was a horse belonging to Abu Talha that used to be slow, but after that day it was never outrun again."