Sunan an-Nasa'i, Volume 5, Book 37, Hadith 4102 (DarusSalam) ⓘ
It was narrated from Ibn Az-Zubair that: The Messenger of Allah [SAW] said: "Whoever unsheathes his sword and starts to strike the people with it, it is permissible to shed his blood."
أَخْبَرَنَا إِسْحَاقُ بْنُ إِبْرَاهِيمَ، قَالَ أَنْبَأَنَا الْفَضْلُ بْنُ مُوسَى، قَالَ حَدَّثَنَا مَعْمَرٌ، عَنِ ابْنِ طَاوُسٍ، عَنْ أَبِيهِ، عَنِ ابْنِ الزُّبَيْرِ، عَنْ رَسُولِ اللَّهِ صلى الله عليه وسلم قَالَ " مَنْ شَهَرَ سَيْفَهُ ثُمَّ وَضَعَهُ فَدَمُهُ هَدَرٌ " .
also referenced under: Hadith 4097 (Reference) & Book 37, Hadith 132 (In-Book)