Narrated Abu Huraira (Radi-Allahu ‘anhum):

The Prophet (Sallallahu ‘Alaihi Wa Sallam) said, “A wound which a Muslim receives in Allah’s cause will appear on the Day of Resurrection as it was at the time of infliction; blood will be flowing from the wound and its color will be that of the blood but will smell like musk.”

Bukhari Vol. 1 : No. 238