Sunan an-Nasa'i 3985
سنن النسائي#3985SahihIt was narrated from 'Abdullah that:The Prophet [SAW] said: "No person is killed wrongfully, but a share of responsibility for his blood will be upon the first son of Adam, because he was the first one to set the precedence, of killing
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: 37:20