It is narrated from Sayyiduna Salman al-Farisi (may Allah be pleased with him) that he said: "I came to the Messenger of Allah (peace and blessings be upon him) with zakah three times." And he (peace and blessings be upon him) asked: "Whom do you count as a martyr among you?" They said: "The one who is killed in the path of Allah." He (peace and blessings be upon him) said: "Then the martyrs of my Ummah would be few. Being killed in the path of Allah is martyrdom, (dying in) the plague is martyrdom, dying in (the state of) childbirth bleeding (nifas) is martyrdom, dying by burning is martyrdom, dying by drowning is martyrdom, death from consumption (a disease of the lungs) is martyrdom, and (dying of) a disease of the stomach is martyrdom."
Imam al-Tabarani (may Allah have mercy on him) said: "No one narrated this hadith from Asim (may Allah have mercy on him) except Mindal (may Allah have mercy on him), and Bakr (may Allah have mercy on him) is alone in narrating it."
Hadith Referenceالمعجم الأوسط / باب الألف / 1243
Hadith Takhrij«أخرجه البزار فى «مسنده» برقم: 2539، والطبراني فى «الكبير» برقم: 6115، 6116»