The Messenger of Allah ﷺ sent me to a man who had married his father's wife after him, with orders to strike his neck, or to kill him.
أخبرنا أحمد بن عثمان بن حكيم قال حدثنا أبو نعيم قال حدثنا الحسن بن صالح عن السدي عن عدي بن ثابت عن البراء قال لقيت خالي ومعه الراية فقلت
أرسلني رسول الله ﷺ إلى رجل تزوج امرأة أبيه من بعده أن أضرب عنقه أو أقتله
[Its chain of transmission is sahih] Tirmidhi narrated it in the Book of Rulings, Chapter on One Who Marries His Father's Wife, Hadith 1362, from the hadith of Adi through this route, and he said, hasan gharib. Ibn Jarud graded it sahih, Hadith 681, and it has other routes in Abu Dawud, Hadith 4456, Ibn Hibban, Hadith 1516, Tirmidhi, and Hakim, 2/191, and others. See the hadith that follows.