Narrated Abu Hazim
The people asked Sahl bin Sa`d As-Sa' idi "With what thing (medicine) was the wound of Allah's Apostle treated?" He replied, "There is none left (living) amongst the people who knows it better than. `Ali used to bring water in his shield and Fatima (i.e. the Prophet's daughter) used to wash the blood off his face. Then a mat (of palm leaves) was burnt and its ash was inserted in the wound of Allah's Apostle."