Musnad Ahmad 1153:2163

Yahya ibn Ishaq narrated to us, he said: Ja'far ibn Kaysan informed me, he said: Mu'adhah narrated to me, she said: I heard 'Aishah saying: The Messenger of Allah, peace and blessings of Allah be upon him, said: "The destruction of my nation is by stabbing and the plague." She said: I said, "O Messenger of Allah, this stabbing we have known, but what is the plague?" He said: "A swelling like the swelling of camels; the one who remains in it is like the martyr, and the one who flees from it is like the one who flees from the battlefield."