During the Prophet's fatal illness, he used to recite the Mu'auwidhat (Surat An-Nas and Surat Al- Falaq) and then blow his breath over his body. When his illness was aggravated, I used to recite those two Suras and blow my breath over him and make him rub his body with his own hand for its blessings." (Maʿmar asked Az-Zuhri: How did the Prophet ﷺ use to blow? Az-Zuhri said: He used to blow on his hands and then passed them over his face.)  

أَنَّ النَّبِيَّ ﷺ كَانَ يَنْفُثُ عَلَى نَفْسِهِ فِي الْمَرَضِ الَّذِي مَاتَ فِيهِ بِالْمُعَوِّذَاتِ فَلَمَّا ثَقُلَ كُنْتُ أَنْفِثُ عَلَيْهِ بِهِنَّ وَأَمْسَحُ بِيَدِ نَفْسِهِ لِبَرَكَتِهَا فَسَأَلْتُ الزُّهْرِيَّ كَيْفَ يَنْفِثُ قَالَ كَانَ يَنْفِثُ عَلَى يَدَيْهِ ثُمَّ يَمْسَحُ بِهِمَا وَجْهَهُ