An Invocation for Pustules

‘Ali b. al-‘Abbas narrated from Muhammad b. Ibrahim al-'Alawi from ‘Ali b Musa from his father from Ja’far b. Muhammad al-Sadiq, peace be upon him, who said: ‘When you feel a pustule (al-bathr) [appearing] put your index finger (al-sabbaba) on it and circle it and say seven times:

“There is no god but Allah, the Clement, the Noble.”

The seventh time, strike it and press on it with your finger.’