Abu Dawud Book 017, Hadith Number 3413.
Chapter : Not known.
Narated By Alaqah ibn Sahar at-Tamimi : Alaqah passed by a clan (of the Arab) who came to him and said: You have brought what is good from this man. Then they brought a lunatic in chains. He recited Surat al-Fatihah over him three days, morning and evening. When he finished, he collected his saliva and then spat it out, (he felt relief) as if he were set free from a bond. They gave him something (as wages). He then came to the Prophet (pbuh) and mentioned it to him. The Apostle of Allah (pbuh) said: Accept it, for by my life, some accept it for a worthless charm, but you have done so far a genuine one.