Sahih Muslim , Book 20, Hadith 4709 (USC-MSA) ⓘ
It has been narrated on the authority of Hafsa daughter of Sirin who said: 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 said that death by plague is martyrdom for a Muslim.
حَدَّثَنَا حَامِدُ بْنُ عُمَرَ الْبَكْرَاوِيُّ، حَدَّثَنَا عَبْدُ الْوَاحِدِ، - يَعْنِي ابْنَ زِيَادٍ - حَدَّثَنَا عَاصِمٌ، عَنْ حَفْصَةَ بِنْتِ سِيرِينَ، قَالَتْ قَالَ لِي أَنَسُ بْنُ مَالِكٍ بِمَا مَاتَ يَحْيَى بْنُ أَبِي عَمْرَةَ قَالَتْ قُلْتُ بِالطَّاعُونِ . قَالَتْ فَقَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " الطَّاعُونُ شَهَادَةٌ لِكُلِّ مُسْلِمٍ " .
also referenced under: Book 33, Hadith 239 (In-Book) & Hadith 1916 (Reference)