Narrated Al-Bara ibn Azib: while I was wandering in search of my camels which had strayed, a caravan or some horsemen carrying a standard came forward. The bedouin began to go round me for my position with the Prophet ﷺ. They came to a domed structure, took out a man from it, and struck his neck. I asked about him. They told me that he had married his father's wife.
Hadith Referenceسنن ابي داود / كتاب الحدود / 4456
Hadith Gradingالألبانی:صحيح | زبیر علی زئی:إسناده صحيح, مشكوة المصابيح (3172)
Benefits and Issues: A woman married by the father is forever prohibited (haram) for the son. It is explicitly stated in Surah An-Nisa: verse 22: (wa la tankihu ma nakaha aba’ukum mina n-nisa’) and the punishment for this crime is death.
Source: Sunan Abu Dawood – Commentary by Shaykh Umar Farooq Saeedi, Page: 4456