Musnad Ahmad 30:184

Sufyan narrated to us, from Abu al-Zinad and Ibn ‘Ajlan, from al-A‘raj, from Abu Hurayrah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) 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." And Sufyan narrated it once solely from Abu al-Zinad.