The Chandogya Upanishad

It is with the incantation of oum that the rites prescribed in the vedas are begun. It is with oum that incantations and hymns are chanted. Sacrifices performed to the chanting of the syllable oum attain the sun-god. They then become rain and the rain become foodgrains. Foodgrains sustain the breath of life. It is thus that oum is nothing but the breath of life.

There are those who know the glory of oum and there are those who do not. Both classes of people perform action and worship and obtain the resultant fruits. But the fruits obtained by those wonderful nature of the syllable oum.

The gods and the demons were both offspring of prajapati. Many years ago, the gods and the demons fought among themselves. In their fight with the demons, the gods enlisted the support of the god of hymns.

The gods elected the power of speech as a chorister and the demons attacked the power of speech with their sins. It is for this reason that men utter the truth, as well as falsehood. The gods elected the power of smell as chorister and the demons attacked the power of smell with their sins. It is for this reason that there are both good smells and bad ones. The gods elected the power of sight as a chorister and the demons attacked the power of sight with their sins. It is for this reason that men see both beautiful sights and ugly ones. The gods elected the power of hearing as a chorister and the demons attacked power of hearing with their sins. It is for this reason that men here both pleasant and unpleasant sounds. The gods elected the mind as a chorister and the demons attacked the mind with their sins. It is for this reason that both god and evil thoughts frequent the minds of men. Finally, the gods elected the breath of life as a chorister. And the demos were decimated as soon as they came into contact with the breath of life, just as a brick crushed by a boulder. The breath of life is like solid stone; it crushes those who perform evil deeds or exhibit hatred.