Sunan an-Nasa'i 4126
سنن النسائي#4126SahihIt was narrated that Ibn 'Umar said:"The Messenger of Allah [SAW] said: 'Do not revert to disbelievers after I am gone, striking the necks of one another (killing one another). No man is to be punished for the sins of his father, or for the sins of his brother
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
In-book reference: 37:161