It was narrated form Al Bara bin Azib that the Prophet said:"Allah will keep firm those who believe, with the world that stands firm in this world, and in the Hereafter. This was revelated concerning the torment in the grave. It will be said to him (the deceased: 'Who is your Lord?' and he will say: 'My Lord is Allah and my Prophet is Muhammad. That is what is (the meaning of) His saying: Allah will keep firm those who believe, with the word that stands firm in this world, and in the Hereafter".
أَخْبَرَنَا مُحَمَّدُ بْنُ بَشَّارٍ، قَالَ حَدَّثَنَا مُحَمَّدٌ، قَالَ حَدَّثَنَا شُعْبَةُ، عَنْ عَلْقَمَةَ بْنِ مَرْثَدٍ، عَنْ سَعْدِ بْنِ عُبَيْدَةَ، عَنِ الْبَرَاءِ بْنِ عَازِبٍ، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ { يُثَبِّتُ اللَّهُ الَّذِينَ آمَنُوا بِالْقَوْلِ الثَّابِتِ فِي الْحَيَاةِ الدُّنْيَا وَفِي الآخِرَةِ } قَالَ نَزَلَتْ فِي عَذَابِ الْقَبْرِ يُقَالُ لَهُ مَنْ رَبُّكَ فَيَقُولُ رَبِّيَ اللَّهُ وَدِينِي دِينُ مُحَمَّدٍ صلى الله عليه وسلم فَذَلِكَ قَوْلُهُ { يُثَبِّتُ اللَّهُ الَّذِينَ آمَنُوا بِالْقَوْلِ الثَّابِتِ فِي الْحَيَاةِ الدُّنْيَا وَفِي الآخِرَةِ } .
Nesai
The Book of Funerals • Hadith 2057