What did the Prophet Muhammad (saw) tell his followers, which was confirmed by Allah's words in the Quran: "Verily! You cannot make the dead to hear (i.e. benefit them, and similarly the disbelievers) nor can you make the deaf hear. (27.80)"?
 Narrated `Aisha:                     The Prophet said, "They now realize that what I used to tell them was the truth. "And Allah said, 'Verily! You cannot make the dead to hear (i.e. benefit them, and similarly the disbelievers) nor can you make the deaf hear. (27.80).