The practice of mantram yoga is well known throughout India as a method of suppressing the wandering tendencies of the mind. A mantram, usually given by a guru or adapted by oneself from a book, is a word or a phrase or even a whole sentence which the practitioner chants to himself or whispers or even mentally utters again and again. Some Sanskrit mantrams are quite meaningless sounds, whereas others are full of metaphysical or religious meaning. Which one is used does not matter from the point of view of acquiring concentration, but it does matter from the point of view of developing any particular quality of character or devotional homage which the mantram symbolizes. This mental or vocal repetition is to be done periodically and faithfully.
-- Notebooks Category 4: Elementary Meditation > Chapter 6 : Mantrams, Affirmations > # 1
-- Perspectives > Chapter 4: Elementary Meditation > # 68
