Question: What is the source of evil thoughts that disturb those who do not wish to entertain them?
Answer by 'Abdu'l-Baha: They come from other minds; they are reflected. One
should not become a mirror for them - to reflect them; neither should one try
to control them, for this is impossible; it only aggravates the difficulty,
causing more to appear.
One should constantly turn the mirror of his heart squarely
toward God so that the Light of the Sun of Truth may be reflected there.
This is the only cure for attacks of evil thoughts. The face
of the mirror should be turned toward God, and the back of the mirror
toward the evil thoughts.
('Abdu'l-Baha, from a table talk, ‘Daily Lessons
Received at Akka January 1908”, by Helen Goodall and Ella Goodall Cooper)