From Sahih Muslim (Hadith 4862):
It has been narrated on the authority of Abu Huraira that the Messenger of Allah (ﷺ) said:One who is wounded in the way of Allah-and Allah knows better who is wounded in His way-will appear on the Day of Judgment with his wound bleediing. The colour (of its discharge) will be the colour of blood, (but) its smell will be the smell of musk
Reference: Muslim 4862