Sunan an-Nasa'i 3331
سنن النسائي#3331SahihIt was narrated that Al-Bara' said:"I met my maternal uncle who was carrying a flag (for an expedition) and I said: 'Where are you going?' He said: 'The Messenger of Allah is sending me to a man who has married his father's wife after he died, to strike his neck or kill him
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 ZaiHasan
In-book reference: 26:136