Sayyiduna Anas (may Allah be pleased with him) said: Once there was a state of alarm in Madinah, so the Prophet (peace and blessings be upon him) rode the horse of Abu Talhah (may Allah be pleased with him), which was called Mandub. He (peace and blessings be upon him) said: "At the time of alarm, we found it to be a sea."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الشهادات / 20850