Hadith 2973
Sayyidah Aisha Siddiqa (may Allah be pleased with her) narrates: When the Prophet Muhammad (peace be upon him) would perform ruqyah (spiritual healing) for a sick person, he would do this as well: he would put his saliva on his finger and recite, "With the name of Allah, seeking blessing from the soil of our land, with the saliva of one of us, so that our sick may be cured by the permission of our Lord."