The Important Point The wives of the prophet once they CHOOSE the prophet and the life after this was final by the Quran they can not be divorced and hence they are the prophets wives even after his death. No one can marry them after the prophet this is why they are called the mothers of the believers in the Quran to finalize any doubts in that regards (who ever has doubt about them being the prophet's wives and the mothers of the believers MUST check his faith if he has any) The Quran includes and specifies the Wives of the prophets as Ahl alBayt in the case of Ibrahim and Lot, etc