OUM ; THAT IS PERFECTLY COMPLETE .

OUM is the vaachak / name of param tatwa / ultimate reality / truth /existence ; atmaa , the Soul . it is also called Pranava.
Purnmadah = That is perfectly complete.
Purnmidam = This is perfectly complete .
Purnaat Purnamudachyate = From that Completeness this Completeness comes out in within .
Purnasya Purnmadaya = This Completeness taken out in within from That Completeness -
Purnameva Vashishyate . = Only The Completeness remains in full .
-Ishavashya - Upnishad ( Brihadranyak Upnishad .)
Note - That = OUM ; This = Cosmos /Creation / Universe / Individual / Plurality .
The spiritual aspect of This and That difference is only caused by duality and then > plurality in this world . even if we separate from That to This ; This is complete as being Absolute Unity ; that That and This both are one appearing as two being the inherent property of THAT .
Here the Absolute Reality is in Scientific term / word , TOTAL ENERGY that can neither be created nor destroyed . this That changes itself it's own form and quality from one to appearing many out of it's own potential . this is so as it is , undescribable but can be realized and felt by us with our own experience .
'' ॐ पूर्णमदः पूर्णमिदं पूर्णात पूर्णमुदच्यते । पूर्णस्य पूर्णमादाय पूर्णमेवोंवशिष्यते ॥
- इशोपनिषद ।