Sri Aurobindo translates Chhandogya Upanishad, Chapter One, Section One, Verses 9-10: “By OM the triple knowledge proceedeth; with OM the priest reciteth the Rik, with OM he pronounceth the Yajur, with OM he chanteth the Sama. And all this is for the heaping up of the Imperishable and by the greatness of It and the delightfulness. He doeth works by OM who hath the knowledge, and he also who hath it not; but these are diverse, the Knowledge and the Ignorance. Whatso work one doeth with knowledge, with faith and with the secret of Veda, it becometh to him more virile and mighty. This is the exposition of the eternal letters.”
The references to the sacrificial chants of the Rig-veda, Yajur-veda and Sama-veda have, once again, a two-fold purpose. The outer purpose is to explain the significance of OM in the rituals, the inner purpose is to remind the seeker that all of these actions are based in and founded upon the Eternal Brahman.
There is a debate then as to whether rote effort done in ignorance has the same result as a similar action done with knowledge. The Vedic Rishis clearly indicate that knowledge makes the work more powerful and fruitful of result. Either way, the power of OM is operative, as it is the Eternal Brahman. We can see this in everyday work-life. Some people work at a job as a mechanical or rote process and they tend to “get the job done” but do not grow or advance quickly as a result. Others may undertake the same job, but with an intention and insight to understand its principles of action and apply them. These individuals turn the job into a growth opportunity and advance more swiftly along the way. Similarly, anything undertaken with ignorance of its action and goal is subject to deviations and errors that can mitigate to a great degree the end result. By applying knowledge and insight, the result can come more directly.
Sri Aurobindo notes: “This then is the meaning of the Upanishad that OM, the syllable, technically called the Udgitha, is to be meditated on as a symbol of the fourfold Brahman with two objects, the ‘singing to’ of one’s desires and aspirations in the triple manifestation and the spiritual ascension into the Brahman Itself so as to meet and enter into heaven after heaven and even into Its transcendent felicity. For, it says, with the syllable OM one begins the chant of the Sama-veda, or, in the esoteric sense, by means of the meditation on OM one makes this soul-ascension and becomes master of all the soul desires. It is in this aspect and to this end that the Upanishad will expound OM. To explain Brahman in Its nature and workings, to teach the right worship and meditation on Brahman, to establish what are the different means of attainment of different results and the formulae of the meditation and worship, is its purpose.”
Sri Aurobindo, The Upanishads, Chhandogya Upanishad, pp.349-366