Sahih Bukhari Volume 3, Book 51, Hadith 2628

حَدَّثَنَا آدَمُ، حَدَّثَنَا شُعْبَةُ، عَنْ قَتَادَةَ، قَالَ سَمِعْتُ أَنَسًا، يَقُولُ كَانَ فَزَعٌ بِالْمَدِينَةِ فَاسْتَعَارَ النَّبِيُّ صلى الله عليه وسلم فَرَسًا مِنْ أَبِي طَلْحَةَ يُقَالُ لَهُ الْمَنْدُوبُ، فَرَكِبَ فَلَمَّا رَجَعَ قَالَ ‏"‏ مَا رَأَيْنَا مِنْ شَىْءٍ، وَإِنْ وَجَدْنَاهُ لَبَحْرًا ‏"‏‏.‏

Narrated 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)."