Sunan Ibn Majah, Volume 5, Book 34, Hadith 3844 (DarusSalam) ⓘ
It was narrated from 'Umar that the : Prophet saas used to seek refuge with Allah from cowardice, miserliness, old age, the torment of the grave and the tribulation of the heart. (Da'if)(One of the narrators) Waki' said: "Meaning when a man dies in a state of tribulation (Fitnah) and does not ask Allah to forgive him."
حَدَّثَنَا عَلِيُّ بْنُ مُحَمَّدٍ، حَدَّثَنَا وَكِيعٌ، عَنْ إِسْرَائِيلَ، عَنْ أَبِي إِسْحَاقَ، عَنْ عَمْرِو بْنِ مَيْمُونٍ، عَنْ عُمَرَ، أَنَّ النَّبِيَّ ـ صلى الله عليه وسلم ـ كَانَ يَتَعَوَّذُ مِنَ الْجُبْنِ وَالْبُخْلِ وَأَرْذَلِ الْعُمُرِ وَعَذَابِ الْقَبْرِ وَفِتْنَةِ الصَّدْرِ . قَالَ وَكِيعٌ يَعْنِي الرَّجُلَ يَمُوتُ عَلَى فِتْنَةٍ لاَ يَسْتَغْفِرُ اللَّهَ مِنْهَا .
also referenced under: Hadith 3844 (Reference) & Book 34, Hadith 18 (In-Book)