Sunan an-Nasa'i 5504
It was narrated from 'Aishah that:
The Prophet [SAW] used to seek refuge with Allah from the torment of the grave and the tribulation of the Dajjal, and he said: "You will be tried in your graves."
أَخْبَرَنَا قُتَيْبَةُ، قَالَ حَدَّثَنَا سُفْيَانُ، عَنْ يَحْيَى، عَنْ عَمْرَةَ، عَنْ عَائِشَةَ، أَنَّ النَّبِيَّ صلى الله عليه وسلم كَانَ يَسْتَعِيذُ بِاللَّهِ مِنْ عَذَابِ الْقَبْرِ وَمِنْ فِتْنَةِ الدَّجَّالِ قَالَ وَقَالَ ‏
"‏ إِنَّكُمْ تُفْتَنُونَ فِي قُبُورِكُمْ ‏"‏ ‏.‏