The Sufi knows of the past, present and future, and about all things in life, by being able to know the direction of sound. Every aspect of one's being in which sound manifests has a peculiar effect upon life, for the activity of vibrations has a special effect in every direction. The knower of the mystery of sound knows the mystery of the whole universe. Whoever has followed the strains of this sound has forgotten all earthly distinctions and differences, and has reached that goal of truth in which all the blessed ones of God unite.