Hadithcore
Sahih al-Bukhari, 1373
sahih

Narrated Asma' bint Abi Bakr:

Allah's Messenger (ﷺ) once stood up delivering a sermon and mentioned the trial which people will face in the grave. When he mentioned that, the Muslims started shouting loudly.

حَدَّثَنَا يَحْيَى بْنُ سُلَيْمَانَ، حَدَّثَنَا ابْنُ وَهْبٍ، قَالَ أَخْبَرَنِي يُونُسُ، عَنِ ابْنِ شِهَابٍ، أَخْبَرَنِي عُرْوَةُ بْنُ الزُّبَيْرِ، أَنَّهُ سَمِعَ أَسْمَاءَ بِنْتَ أَبِي بَكْرٍ ـ رضى الله عنهما ـ تَقُولُ قَامَ رَسُولُ اللَّهِ صلى الله عليه وسلم خَطِيبًا فَذَكَرَ فِتْنَةَ الْقَبْرِ الَّتِي يَفْتَتِنُ فِيهَا الْمَرْءُ، فَلَمَّا ذَكَرَ ذَلِكَ ضَجَّ الْمُسْلِمُونَ ضَجَّةً‏.‏

References2 variants
In-Book Reference
Book 23, Hadith 125
USC-MSA web (English) reference
Vol. 2, Book 23, Hadith 455 (deprecated numbering scheme)
Sharh · explanationclick to expand
The Prophet ﷺhad [many] miracles that testify to the truthfulness of his message and his prophethood, one of which is his description of some of the events of the unseen, which Allah revealed to him. The unseen could be about matters pertaining to Allah’s reward or punishment; and he ﷺ mentions these to warn his nation, and to encourage them perform more good deeds and refrain from evil and bad deeds. In this hadeeth, Asmaa’ bint Abee Bakr(may Allah be pleased with her) reports that the Prophet ﷺ delivered a sermon one day, in which he preached to them and reminded them of the Hereafter. He ﷺ then spoke of the grave and its related events, including the trial of the grave. The trial of the grave is a test where the two angels, Munkar and Nakeer, ask the deceased about his lord, prophet, and religion. In Arabic, it is known as the fitnah of grave, this Arabic word was assigned to it because it is a great trial that tests the person’s faith and certainty. Whomever Allah gives support to, to pass this test is a winner, and whoever fails is ruined, and at a great loss. Asmaa’ (may Allah be pleased with her) mentioned that after hearing about the trial of the grave, the companions shouted out loud, out of fear of what they had heard. In another version of the narration, it has the addition: “the punishment of the grave is true”, meaning that it is without a doubt confirmed that it must be believed in. .