Sahih al-Bukhari, Volume 8, Book 73, Hadith 231 (USC-MSA) ⓘ

Narrated Anas bin Malik: There was a state of fear in Medina. Allah's Messenger rode a horse belonging to Abu Talha (in order to see the matter). The Prophet said, "We could not see anything, and we found that horse like a sea (fast in speed).

حَدَّثَنَا مُسَدَّدٌ، حَدَّثَنَا يَحْيَى، عَنْ شُعْبَةَ، قَالَ حَدَّثَنِي قَتَادَةُ، عَنْ أَنَسِ بْنِ مَالِكٍ، قَالَ كَانَ بِالْمَدِينَةِ فَزَعٌ فَرَكِبَ رَسُولُ اللَّهِ صلى الله عليه وسلم فَرَسًا لأَبِي طَلْحَةَ فَقَالَ ‏ "‏ مَا رَأَيْنَا مِنْ شَىْءٍ، وَإِنْ وَجَدْنَاهُ لَبَحْرًا ‏" ‏‏.‏