1. Preamble of Om tat sat. After consideration of Yoga the title of our work, and all its component parts tending to the exercise of meditation, together with an investigation into the nature of Átman or soul, as the agent of the act of meditating and procuring its salvation, we are led by a natural and coherent train of thought to an inquiry into the nature of that grand object of our holy and profound meditation, which is the only means of our emancipation, and which is presented at once to our view in the exordium of the work in the mystical characters of Om Tat Sat = On Id Est.
2. Ambiguity of the word Om. The word Om forming the initial of the said epigraph standing prominent at the top of the opening page of the work, and being more than a multinymous term and ambiguous in its acceptations, requires to be treated at some length, in order to discover the hidden meaning lying buried under that mystic emblem of the grand arcanum of Brahmanical and Universal religion, from amidst a variety of significations which are heaped upon it in the sacred writings and holy speculations of the early sages of India.
The Sruti Says:—
3. In the beginning was the word Om. ॐमित्येवमग्रमासीत् । प्रथम मोङ्कारात्मकमासीत् । तस्माच्च निःसृताः सर्ब्बे, प्रलीयन्ते तत्रवै । So saith the Holy scripture:—
“In the beginning was the word, the word was with God, and the word was God. All this was made by him, and without him was not anything made, that was made and” St. John 1.1-3.
Om, the light of the world. And again says the Sruti दीप्यतोँ ज्योतिः । तत्तेजोऽनेनैवोमित्येव तदुद्बुध्न्यति । मैत्री उप ७ ।११
“That Om shone forth as light, but they received it not, and hid it in darkness.” So the Scripture:—
“That was the light of the world, and the light shone upon the world, but the world knew it not &c.” St. John, Ch 1, V. 5. 9. 10.
5. Its Revelation to mankind. Again says the Scripture:—“God sent one to bear witness of the light, that all men through him might believe.” Id 1.7. So Brahmá the god revealed its meaning to his first begotten son Atharvan, and Atharvan, the Prajápati, gave instruction on the subject to Pippaláda, Sanatkumára and Angira (Weber A. S. L., p. 164). Again Angiras, who communicated it to Saunaka, had obtained it from Bharadvája Satyaváha, and the latter again from Ángira, the pupil of Atharvan, to whom it was revealed by Brahmá himself (Weber A. S. L., p. 158).
6. Works on its Disquisition. Hence it is the Atharva Sikhá Upanishad in which the investigation of the sacred word Om is principally conducted apart from those of the Mándukya, Maitrí and Táraka Upanishads. (Web. Id., p. 164). These together with their Bháshyas by Sankara, the Kárikás of Gaudapáda, and the commentaries of Ánandagiri on them, are chiefly devoted to the scrutiny of the sacred syllable, beside the partial disquisition of every other Upanishad and theological work into the hidden sense of this mystic word. Weber points out the Saunaka and Pranava Upanishads among the number (A. S. L., p. 165).