Sunan Abi Dawud, Book 8, Hadith 1515 (USC-MSA) ⓘ
Sahl b. Hunaif reported: The Messenger of Allah said: If anyone asks Allah for martyrdom sincerely, Allah will make him reach the ranks of martyrs even if he died on his bed.
حَدَّثَنَا يَزِيدُ بْنُ خَالِدٍ الرَّمْلِيُّ، حَدَّثَنَا ابْنُ وَهْبٍ، حَدَّثَنَا عَبْدُ الرَّحْمَنِ بْنُ شُرَيْحٍ، عَنْ أَبِي أُمَامَةَ بْنِ سَهْلِ بْنِ حُنَيْفٍ، عَنْ أَبِيهِ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " مَنْ سَأَلَ اللَّهَ الشَّهَادَةَ صَادِقًا بَلَّغَهُ اللَّهُ مَنَازِلَ الشُّهَدَاءِ وَإِنْ مَاتَ عَلَى فِرَاشِهِ " .
also referenced under: Hadith 1520 (DarusSalam) & Hadith 1515 (Hasan)