Sunan an-Nasa'i 4869
سنن النسائي#4869SahihIt was narrated that Ibn 'Abbas said:"The Messenger of Allah said: 'No one who commits Zina is a believer at the moment when he is committing Zina, and no one who drinks wine is a believer at the moment when he is drinking it, and no thief is a believer at the moment when he is stealing, and no killer is a believer at the moment he is 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 Bukhari
In-book reference: 45:164