It has been narrated on the authority of Abd-ul-'Aziz b. Abu Hazim, who learnt from his father (Abu Hazim). The latter heard it from Sahl b. Sa'd who was asked about the injury which the Messenger of Allah (ﷺ) got on the day of the Battle of Uhud. He said:
The face of the Messenger of Allah (ﷺ) was injured, his front teeth were damaged and his helmet was crushed. Fatima, the daughter of the Messenger of Allah (ﷺ), was washing the blood (from his head), and 'Ali b. Abu Talib was pouring water on it from a shield. When Fatima saw that the bleeding had increased on account of (pouring) water (on the wound), she took a piece of mat and burnt it until it was reduced to ashes. She put the ashes on the wound and the bleeding stopped.