This chant is a Shanti mantra (peace invocation) and appears primarily in Isha Upanishad (Ishopanishad) or many times called Ishavasya Upanishad (one of the primeval Upanishad). This mantra is commonly chanted as a prayer before the study of Upanishad begins.
Practicing Vedic mantras systematically, diligently, with total concentration will lead you to a state of complete healing energy, and this will allow your physical, mental and energetical body to regain its natural state.
To truly understand the transformative power the Vedic mantras, we need to realize that any form of sound in the creation is vibrational energy. Human speech and words are also a combination of sound waves (vibration), each of which resonates at distinct vibrational frequencies.
This small mantra contains the essence of the Upanishadic vision… Nothing is insignificant, nothing is smaller than anything else. The part represents the whole just as the seed contains the whole.” – Osho
Om Purnam Adah Purnam Idam mantra complete lyrics in Sanskrit:
”Om Purnamadah Purnamidam Purnat Purnamudachyate
Purnasya Purnamadaya Purnamevavashisyate
Om, shanti, shanti, shanti.”
Om Purnamadah Purnamidam mantra meaning:
”THAT is infinite, THIS is infinite; From That, This comes. THIS added or removed from THAT, the Infinite remains as Infinite. Om, peace, peace, peace.”
”You are the fullness. There is fullness, here is fullness. From the fullness, the fullness is born. Remove the fullness from the fullness and the fullness alone remains.”
The meaning of this ancient Vedic mantra is that the whole creation constitutes one whole unit. Each and every particle, non-living or living represents the same whole unit. There is no place where this whole is not present. This whole reproduces itself in its own image. Removing every entity from this unit has no effect on it because that which remains represents the same whole.