Literally, the word mantra means ‘revealed sound’. According to the ancient texts, mantra means a sound or a combination or sequences of sounds which develop spontaneously. These sounds were revealed to rishis and other pure beings in psychic states or in very deep meditation, when all consciousness of the self was lost and when nothing but inner light shone in front of them.
Mantra do not have any specific meaning. Their power is not in the words themselves, but in the sound vibrations created when the mantra is uttered verbally or when it takes form in the mind and is not expressed in the voice.