أَخْبَرَنَا يُونُسُ بْنُ عَبْدِ الأَعْلَى، قَالَ حَدَّثَنَا ابْنُ وَهْبٍ، قَالَ حَدَّثَنِي عَبْدُ الرَّحْمَنِ بْنُ شُرَيْحٍ، أَنَّ سَهْلَ بْنَ أَبِي أُمَامَةَ بْنِ سَهْلِ بْنِ حُنَيْفٍ، حَدَّثَهُ عَنْ أَبِيهِ، عَنْ جَدِّهِ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ ‏"‏ مَنْ سَأَلَ اللَّهَ عَزَّ وَجَلَّ الشَّهَادَةَ بِصِدْقٍ بَلَّغَهُ اللَّهُ مَنَازِلَ الشُّهَدَاءِ وَإِنْ مَاتَ عَلَى فِرَاشِهِ ‏"‏ ‏.‏

Sahl bin Abi Umamah bin Sahl bin Hunaif narrated from his father, from his grandfather, that the Messenger of Allah (PBUH) said: "Whoever asks Allah, the mighty and Sublime, sincerely for martyrdom, Allah will cause him to reach the status of the martyrs even of he dies in his bed." Translation Not Available

Book Ref: Sunan An Nisai Book 25 Hadith 3162
Web Ref:  Sunan An Nisai Vol 1 Book 25 Hadith 3164