The Law of Mantras.
Each mantra is a linkage to a certain aspect of the absolute, a certain manifestation of Divinity. In true mantra practice, one forgets the fact that the self is chanting, becomes the mantra itself, and attains the state where nothing but the mantra exists. One's being then connects with the higher being the mantra represents if it is the name of a Master Being, or connects with the ray of light emanating from God if it is a sound (aum or om, hu, etc.). The practice of chanting mantras is profoundly beneficial in raising the vibration of self.