Sayyiduna al-Bara' (may Allah be pleased with him) said: My maternal uncle Sayyiduna Abu Burdah (may Allah be pleased with him) passed by me with a banner, so I asked: Where are you going? He said: "The Messenger of Allah (peace and blessings be upon him) has sent me to a man who married his father's wife, so that I bring back his head."
Hadith Referenceالمعجم الكبير للطبراني / باب الهاء / 18730