Jami` at-Tirmidhi 1686
جامع الترمذي#1686Sahihحَدَّثَنَا مُحَمَّدُ بْنُ بَشَّارٍ، حَدَّثَنَا مُحَمَّدُ بْنُ جَعْفَرٍ، وَابْنُ أَبِي عَدِيٍّ، وَأَبُو دَاوُدَ قَالُوا حَدَّثَنَا شُعْبَةُ، عَنْ قَتَادَةَ، عَنْ أَنَسِ بْنِ مَالِكٍ، قَالَ كَانَ فَزَعٌ بِالْمَدِينَةِ فَاسْتَعَارَ رَسُولُ اللَّهِ صلى الله عليه وسلم فَرَسًا لَنَا يُقَالُ لَهُ مَنْدُوبٌ فَقَالَ " مَا رَأَيْنَا مِنْ فَزَعٍ وَإِنْ وَجَدْنَاهُ لَبَحْرًا " . قَالَ أَبُو عِيسَى هَذَا حَدِيثٌ حَسَنٌ صَحِيحٌ .
Narrated Anas bin Malik: "There was a cause of fright in Al-Madinah. So the Messenger of Allah (ﷺ) borrowed a horse of ours called Mandub. He said: 'I have not seen anything to be frightened of, and we found him to be (quick) like the sea.'" [Abu 'Eisa said:] This Hadith is Hasan Sahih
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
In-book reference: 23:17