Anas b. Malik asked me the cause of death of Yahya b. 'Abu 'Amra. I said: (He died) of plague. He said: The Messenger of Allah ﷺ said that death by plague is martyrdom for a Muslim. (Using translation from Muslim 1916a)
قَالَ رَسُولُ اللهِ ﷺ الطَّاعُونُ شَهَادَةٌ لِكُلِّ مُسْلِمٍ