Sahih Muslim 1790 a
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.
حَدَّثَنَا يَحْيَى بْنُ يَحْيَى التَّمِيمِيُّ، حَدَّثَنَا عَبْدُ الْعَزِيزِ بْنُ أَبِي حَازِمٍ، عَنْ أَبِيهِ، أَنَّهُ سَمِعَ سَهْلَ بْنَ سَعْدٍ، يُسْأَلُ عَنْ جُرْحِ، رَسُولِ اللَّهِ صلى الله عليه وسلم يَوْمَ أُحُدٍ فَقَالَ جُرِحَ وَجْهُ رَسُولِ اللَّهِ صلى الله عليه وسلم وَكُسِرَتْ رَبَاعِيَتُهُ وَهُشِمَتِ الْبَيْضَةُ عَلَى رَأْسِهِ فَكَانَتْ فَاطِمَةُ بِنْتُ رَسُولِ اللَّهِ صلى الله عليه وسلم تَغْسِلُ الدَّمَ وَكَانَ عَلِيُّ بْنُ أَبِي طَالِبٍ يَسْكُبُ عَلَيْهَا بِالْمِجَنِّ فَلَمَّا رَأَتْ فَاطِمَةُ أَنَّ الْمَاءَ لاَ يَزِيدُ الدَّمَ إِلاَّ كَثْرَةً أَخَذَتْ قِطْعَةَ حَصِيرٍ فَأَحْرَقَتْهُ حَتَّى صَارَ رَمَادًا ثُمَّ أَلْصَقَتْهُ بِالْجُرْحِ فَاسْتَمْسَكَ الدَّمُ ‏.‏