Sunan an-Nasa'i 4116
سنن النسائي#4116SahihIt was narrated that Abu Bakrah said:"The Messenger of Allah [SAW] said: 'If a Muslim points a weapon at his fellow Muslim, then they are on the brink of Hell, and if he kills him, then they will both fall into it
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Abu GhuddahSahih
Al-AlbaniSahih
Zubair Ali ZaiSahih - Agreed Upon
In-book reference: 37:151