Prophet's Wives After His Death
Sura Ahzab tells that the hypocrites were trying to scandalize the house of the prophet. They were trying to get prophet’s wives divorced to make them marry to some other people and that way they might use them against the prophet. Allah shut down this door by declaring that not only the prophet cannot divorce his wives nor can they marry after him. But before this the wives were given the option to leave the prophet if they did not want these restrictions. But none of them left the prophet.
Peer naseer ud din naseer sahab once used this ( allah not giving permission to marry Prophet’s wives after his death ) to prove the living of Prophet in this world after his death. Thats where question came from.