Sahih Bukhari
Funerals (Al-Janaaiz)
Volume: 002 / Book Number: 023 / Hadith Number: 453
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).