The popular Ishopanishad (and some others) begin with the following invocation:

     Purnam Idam, Purnam Adaha (*)

     पूर्णमिदं पूर्णमदः 

     [This is perfect and complete, That is perfect and complete]

     Purnaat Purnam Udachyathe

     पूर्णात् पूर्णमुदच्यते  

     [The perfect and complete arises from the state of perfection and completeness]

     Purnasya Purnam Adaya

     पूर्णस्य पूर्णमादाय

     [When the perfect and complete yields the perfect and complete]

     Purnam Eva Avasishyathe

     पूर्णमेवावशिष्यते॥

     [What remains is only perfect and complete] (**)

Note:

(*) This is the correct order, which is obvious from the end-rhyming of alternate verses.

The primary message is that the world (or everything we observe) is perfect and complete. Also that the world arises from a state of perfection and completeness (The Godhead) which remains undiminished by that act.

An important intent of the invocation is to reassure the reader that, despite any appearances to the contrary, despite any conflicts, woes and suffering endured, his or her life and the world at large is in perfect order and guidance from on high, and therefore the reader can be at peace. This state of mind is considered a requirement to the reading of scripture that follows. Hence the invocation is also called a shanti (peace) mantra.

(**) In addition to rhyming, this Sanskrit composition on Perfection consists of seven phrases, each of which start with the word ‘purnam’ which means ‘perfect and complete’. And seven is the number mystically associated with perfection. The source of this ancient composition has thus made even the construction of the verses ‘perfect’ !