Musnad Ahmad 32:1391

'Affan narrated to us, 'Abd al-Wahid ibn Ziyad narrated to us, 'Asim al-Ahwal narrated to us, Hafsah bint Sirin narrated to me, she said: Anas ibn Malik said to me: "Of what did Yahya ibn Abi 'Amrah die?" I said: "Of the plague." Anas ibn Malik said: The Messenger of Allah, peace and blessings of Allah be upon him, said: "The plague is martyrdom for every Muslim."