Sahih al-Bukhari 2866
Sahih al-Bukhari · Book 56: Fighting for the Cause of Allah (Jihaad) · The riding of an unsaddled horse
Narrated Anas:
حَدَّثَنَا عَمْرُو بْنُ عَوْنٍ ، حَدَّثَنَا حَمَّادٌ ، عَنْ ثَابِتٍ ، عَنْ أَنَسٍ ـ رضى الله عنه اسْتَقْبَلَهُمُ النَّبِيُّ صلى الله عليه وسلم عَلَى فَرَسٍ عُرْىٍ، مَا عَلَيْهِ سَرْجٌ، فِي عُنُقِهِ سَيْفٌ.
The Prophet (ﷺ) met them (i.e. the people) while he was riding an unsaddled horse with his sword slung over his shoulder.