Narrated 'Aisha:

The Prophet, during his fatal ailment used to blow (on his hands and pass them) over his body while reciting the Mu'auwidhat (Surat-an-Nas and Surat-al-Falaq). When his disease got aggravated, I used to recite them for him and blow (on his hands) and let him pass his hands over his body because of its blessing. (Ma'mar asked Ibn Shihab: How did he use to do Nafth? He said: He used to blow on his hands and then pass them over his face.)

حَدَّثَنِي عَبْدُ اللَّهِ بْنُ مُحَمَّدٍ الْجُعْفِيُّ، حَدَّثَنَا هِشَامٌ، أَخْبَرَنَا مَعْمَرٌ، عَنِ الزُّهْرِيِّ، عَنْ عُرْوَةَ، عَنْ عَائِشَةَ ـ رضى الله عنها ـ أَنَّ النَّبِيَّ ﷺ كَانَ يَنْفِثُ عَلَى نَفْسِهِ فِي مَرَضِهِ الَّذِي قُبِضَ فِيهِ بِالْمُعَوِّذَاتِ، فَلَمَّا ثَقُلَ كُنْتُ أَنَا أَنْفِثُ عَلَيْهِ بِهِنَّ، فَأَمْسَحُ بِيَدِ نَفْسِهِ لِبَرَكَتِهَا. فَسَأَلْتُ ابْنَ شِهَابٍ كَيْفَ كَانَ يَنْفِثُ قَالَ يَنْفِثُ عَلَى يَدَيْهِ، ثُمَّ يَمْسَحُ بِهِمَا وَجْهَهُ.