Musnad Ahmad 788:44

'Abd al-Rahman narrated to us, Sufyan narrated to us, from Ziyad ibn 'Alaqah, from a man, from Abu Musa, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "The destruction of my nation will be by the spear-thrust (al-ta'n) and the plague (al-ta'un)." It was said: "O Messenger of Allah, this spear-thrust we have known, but what is the plague?" He said: "The pricking of your enemies from among the jinn, and in everything there is martyrdom."