Sahih Bukhari Volume 3, Book 47, Hadith Number 795.

Narated By Anas : Once the people of Medina were frightened, so the Prophet borrowed a horse from Abu Talha called Al-Mandub, and rode it. When he came back he said, “We have not seen anything (to be afraid of), but the horse was very fast (having an energy as inexhaustible as the water of the sea).”