Meaning
Peace is the whole of what shanti means, and the word is said three times because the Upanishadic peace invocations address three sources of disturbance: what comes from the elements and fate, what comes from other beings and surroundings, and what arises in one's own body and mind. Om opens the line as the sound of the whole. Vedic tradition asks for quiet on all three fronts at once.
त्रिविध शान्ति: आधिभौतिक, आधिदैविक, आध्यात्मिक।