The Prophet ﷺ said, "Whoever sincerely asks Allah for martyrdom, Allah will raise him to the ranks of the martyrs, even if he dies in his bed."
أن النبي ﷺ قال: من سأل الشهادة بصدق، بلغه الله منازل الشهداء وإن مات على فراشه.
Muslim narrated it in "the Book of Leadership" (1909:157) via Abdullah bin Wahb, who said, "Abu Shurayh told me that Sahl bin Abu Umama bin Sahl bin Hunayf told him, on the authority of his father, on the authority of his grandfather," and he related it.