Musnad Abu Ya'la al-Mawsili 159:15

Abu Khaythama narrated to us, Sufyan narrated to us, from Abu al-Zinad, from al-A'raj, from Abu Hurayrah, from the Prophet (peace be upon him), who said: "No one is wounded in the way of Allah—and Allah knows best who is wounded in His way—except that he will come on the Day of Resurrection with his wound gushing blood; the color is the color of blood, and the scent is the scent of musk."