Hadith 4099

It was narrated that Ibn Az-Zubair said: "Whoever wields a weapon and starts to strike (the people) with it, it is permissible to shed his blood."

أَخْبَرَنَا أَبُو دَاوُدَ، قَالَ حَدَّثَنَا أَبُو عَاصِمٍ، عَنِ ابْنِ جُرَيْجٍ، عَنِ ابْنِ طَاوُسٍ، عَنْ أَبِيهِ، عَنِ ابْنِ الزُّبَيْرِ، قَالَ مَنْ رَفَعَ السِّلاَحَ ثُمَّ وَضَعَهُ فَدَمُهُ هَدَرٌ ‏.‏

Reference: 1141140
In-book reference: Book 37, Hadith 4099
Hadith 4099 - The Book of Fighting [The Prohibition of Bloodshed] - Sunan an-Nasa'i - Sunnah.com