The Prophet (ﷺ) looked at the people of the well (the well in which the bodies of the pagans killed in the Battle of Badr were thrown) and said, "Have you found true what your Lord promised you?" Somebody said to him, "You are addressing dead people." He replied, "You do not hear better than they but they cannot reply."
Sahih al-Bukhari Book 23, Hadith 122
← Previous Hadith The Prophet (p.b.u.h) said, "When a faithful believer is made to sit in his grave, then (the angels) come to him and he testifies that none has the right to be worshipped but Allah and Muhammad is Allah's Apostle. And that corresponds to Allah's statement: Allah will keep firm those who believe with the word that stands firm . . . (14.27).

Narrated Shu'ba:

Same as above and added, "Allah will keep firm those who believe . . . (14.27) was revealed concerning the punishment of the grave."

Sahih al-Bukhari Book 23, Hadith 121 Next Hadith → The Prophet (ﷺ) 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).

Sahih al-Bukhari Book 23, Hadith 123