The Messenger of Allah ﷺ said, "Whoever dies from pleurisy is a martyr."
حدثنا حسن حدثنا ابن لهيعة حدثنا وهب بن عبد الله عن عبد الرحمن بن شماسة
أن رسول الله ﷺ قال الميت من ذات الجنب شهيد
No references are available.
Its chain of transmission is hasan, and Haythami also graded it hasan (2/317). Its meaning has preceded many times.