So by meditating on the second syllable, one lives and enjoys the world that he visualises, with his imagination. For the moon (luna) is associated with imagination, visualisation, creativity of thought, which when it goes beyond one’s control becomes lunacy, derived from luna for moon, you know that.
Maybe it is better to be more lunatic, than be a perfect saintly person who does acts of such terrible consequences. Anyway, that is a different story; we won’t discuss that now. So, he becomes an expert by meditating on the Aaa Uuu, Au sound; and being able to work on the creative aspect of his mind and having experienced the greatness there, he returns again to this earth, to further evolve to greater levels of understanding.
But, if he meditates on the highest person, with the three syllables, the three elements of Aum, Aaa Uuu and Mmm, he becomes one with the light, which is the Sun. Just as a snake is freed from its skin, even so is he freed from his sins. He is led by the chanting of the Sama hymns to the world of Brahman.
He sees the person that dwells in the body, who is higher than the highest life. The three elements, each lead to death by themselves, if separately practiced. If they are united to each other, without being separated and employed in actions well performed–external, internal and intermediate–the knower does not waver. He moves forward.
The Aum is the essence of the Rig, the Yajus and the Saman.