"There was a cause of fright in Al-Madinah. So the Messenger of Allah (ﷺ) borrowed a horse of ours called Mandub. He said: 'I have not seen anything to be frightened of, and we found him to be (quick) like the sea.'"

This Hadith is Hasan Sahih.
Jami` at-Tirmidhi Book 23, Hadith 17
← Previous Hadith "The Prophet (ﷺ) rode a horse belonging to Abu Talhah called Mandub. He said: 'There is nothing to be frightened of, and we found him to be (quick) like the sea.'"

There is something on this topic from Ibn 'Amr Al-'As.

Jami` at-Tirmidhi Book 23, Hadith 16 Next Hadith → "The Prophet (ﷺ) was the nicest person among the people, the most generous of the people, and the bravest among the people." He said: "The inhabitants of Al-Madinah became freightened one night upon hearing a loud noise." He said: "So the Prophet (ﷺ) met them upon an unsaddled horse belonging to Abu Talhah, with a sword hanging around his neck. He said: 'I found him to be (quick) like the sea.'" - meaning the horse.

This Hadith is Hasan Sahih.

Jami` at-Tirmidhi Book 23, Hadith 18