Musnad Ahmad 658:142

Yahya ibn Abi Bukayr narrated to us, Abd al-Ghaffar ibn al-Qasim narrated to us, 'Adi ibn Thabit narrated to me, he said: Yazid ibn al-Bara' narrated to me, from his father, who said: I met my maternal uncle, and he had a banner with him. I said: "Where are you heading?" He said: "The Messenger of Allah, may Allah bless him and grant him peace, sent us to a man from Banu Tamim who had married his father's wife after him, and he commanded us to kill him and take his wealth." He said: So they did that. Abu Abd al-Rahman said: "My father did not narrate from Abu Maryam Abd al-Ghaffar except this hadith, due to his weakness."