The Prophet ﷺ said, "The martyrs and those who died from the plague will come forward, and those who died from the plague will say, 'We are martyrs.' It will be said, 'Look. If their wounds are like the wounds of the martyrs, flowing with blood that has the scent of musk, then they are martyrs.' They will find them to be just so."
عن النبي ﷺ قال: يأتي الشهداء والمتوفون بالطاعون فيقول أصحاب الطاعون: نحن شهداء فيقال: انظروا فإن كانت جراحهم كجراح الشهداء تسيل دما ريح المسك فهم شهداء فيجدونهم كذلك.
Ahmad (17651) narrated it from Hakam bin Nafi, who said, Ismail bin Ayyash told us, from Damdam bin Zura, from Shurayh bin Ubayd, from Utba bin Abdul-Sulami, and he mentioned it.Its chain is hasan, for Ismail bin Ayyash is truthful in his narrations from the people of Syria, and Damdam bin Zura is a truthful narrator from Homs. Ibn Hajar graded its chain hasan in Fath al-Bari (10/194), and he likewise said in Bazl Maun (p. 196), "This is a hasan hadith."