Qatadah (may Allah have mercy on him) narrates that he heard Anas bin Malik (may Allah be pleased with him) say: There was fear of the enemy in Madinah, and the Messenger of Allah (peace and blessings be upon him) borrowed a horse from Abu Talhah (may Allah be pleased with him) called al-Mandub. He (peace and blessings be upon him) rode it, and when he returned he said: "We did not see anything to fear, but we found this (horse) to be like the sea."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الإقرار / 11472