Sunan Abi Dawud, Hadith 4732

Al-Bara’ b. ‘Azib reported the Messenger of Allah as saying: When a Muslim is questioned in the grave he testifies that there is no god but Allah and that Muhammad is Allah’s Apostle. That is verified by Allah’s words: “Allah establishes those who believe with the word that stands firm.”

حَدَّثَنَا أَبُو الْوَلِيدِ الطَّيَالِسِيُّ، حَدَّثَنَا شُعْبَةُ، عَنْ عَلْقَمَةَ بْنِ مَرْثَدٍ، عَنْ سَعْدِ بْنِ عُبَيْدَةَ، عَنِ الْبَرَاءِ بْنِ عَازِبٍ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ ‏:‏ ‏"‏ إِنَّ الْمُسْلِمَ إِذَا سُئِلَ فِي الْقَبْرِ فَشَهِدَ أَنْ لاَ إِلَهَ إِلاَّ اللَّهُ وَأَنَّ مُحَمَّدًا رَسُولُ اللَّهِ صلى الله عليه وسلم فَذَلِكَ قَوْلُ اللَّهِ عَزَّ وَجَلَّ ‏{‏ يُثَبِّتُ اللَّهُ الَّذِينَ آمَنُوا بِالْقَوْلِ الثَّابِتِ ‏}‏ ‏.‏

sunnah.com

also referenced under: Hadith 4750 (DarusSalam)