Sahih Muslim Book 19, Hadith Number 4414.

Chapter : The battle of Uhud.

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 (may peace be upon him) got on the day of the Battle of Uhud. He said: The face of the Messenger of Allah (may peace be upon him) was injured, his front teeth were damaged and his helmet was crushed. Fatima, the daughter of the Messenger of Allah (may peace be upon him), 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.