(27) باب حَرْقِ الْحَصِيرِ لِيُسَدَّ بِهِ الدَّمُ
Narrated Sahl bin Saud As-Sa`idi:
When the helmet broke on the head of the Prophet (ﷺ) and his face became covered with blood and his incisor tooth broke (i.e. during the battle of Uhud), `Ali used to bring water in his shield while Fatima was washing the blood off his face. When Fatima saw that the bleeding increased because of the water, she took a mat (of palm leaves), burnt it, and stuck it (the burnt ashes) on the wound of Allah's Apostle, whereupon the bleeding stopped.
Reference: Sahih al-Bukhari 5722
In-book reference: Book 76, Hadith 37
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 7, Book 71, Hadith 618