Fighting for the Cause of Allah (Jihaad)
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.Narrated Anas:The Prophet (ﷺ) met them (i.e. the people) while he was riding an unsaddled horse with his sword slung over his shoulder
From Sahih al-Bukhari, whose reports the scholars accept as authentic.