Sunan an-Nasa'i 4007
سنن النسائي#4007SahihIt was narrated from Zaid with regard Allah's saying:"And whoever kills a believer intentionally, his recompense is Hell" that he said: "This Verse was revealed eight months after the Verse that is in Tabark Al-Furqan: "And those who invoke not any other ilah (god) along with Allah, or kill such person as Allah has forbidden, except by right
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Abu GhuddahHasan Sahih
Al-AlbaniHasan Sahih
Zubair Ali ZaiHasan
In-book reference: 37:42