4. Om is Brahma. ब्रह्म । Om is the verbal symbol of Brahma signifying the Universal spirit ॐ ब्रह्मणि च । ब्रह्मणः नामबिशेषः तारानाथः so says the Katha Upanishad एतद्ध्येबाक्षरं ब्रह्म । This meaning is obtained from ॐ = om signifying being or existence, and referring to the totality of existence expressed by the word Brahma (formed of बृह + मन) universal pervasion.
5. Greatness of Brahma ब्रह्मत्वं बृहत्वञ्च । Om is used also to denote the vast magnitude of Brahma (ब्रह्मत्वं बाबृहत्वं) in the Maitrí Upanishad, which says “Om is the greatness of Brahman, says one who continually meditates thereon.” (See Cowell’s Translation of Id. IV. 4. p. 253). This idea is naturally suggested by the infinity of the Universe pervaded and encompassed by the spirit of God. सर्ब्बं बिन्दु गतं ह्यैतत् ब्रह्माण्डञ्चापिकोटिशः । गायत्री तन्त्रं । The Ch’hándogya Upanishad speaks of the greatness and effects of Om (I. 9). To this the scholium raises the question, what are its greatness and effects? Then answers it by saying;—“by the greatness of Om is implied the existence of priests, the institutions of sacrifices &c. &c. Therefore is its greatness.”
6. Om is the way to Brahma ब्रह्मज्ञानोपायः । “Om,” says the Mándukya Upanishad, “is the means (symbol) leading to Brahma,” as a hieroglyphic character to its significate. Here says the commentator Ánandagiri (p.336.) ओङ्कारो ब्रह्म वुद्ध्योपास्य मानो ब्रह्म प्रतिपत्युपायो भबतीति । आनन्दगिरि टीका । “It is known in all the Vedántas as the best means towards the accomplishment of one’s adoration.” (Ch’hándogya Upanishad p. 5 note.)
7. Immutable & Imperishable ॐ अक्षरः । It is immutable, undecayable, imperishable, indestructible and immortal (अक्षरं). Thus in the Mándukya; ओमित्येतदक्षरमिदं बिकार रहितमित्यादि । The circle of O is considered the most perfect of all geometrical figures, as it was held by the Pythagoreans to be the best symbol to represent the perfections of the Supreme Being. It is the sign of divine immutability from the fact of every other figure changing its shape by its constant rotation round the centre and becoming a spheroid which is no more susceptible of change. Such is the changeable nature of all things until they become one with the Divinity.
Om Knowable. ज्ञेयं । Om the symbol of God is said to be the knowable, because every part of its circumference is equidistant from the central observer. So is God said to be knowable (ज्ञेय) in Yoga philosophy for his knowableness to every one by means of meditation. Hence the Yoga system is called gnosticism contrary to the unknowableness of agnosticism.
8. Eternity नित्यं । Om is called eternal (नित्यं), because its circular form is the representation of eternity, having neither its beginning nor end (अनाद्यनन्तं): so it is the symbol of infinity, the circle being described by an infinite line. Thus Gaudapáda; अपूर्व्वोऽनन्तरोऽनन्तः नपरः प्रणबाब्यय । इति माण्डुक्य कारिकायां । १६ ।
9. The First and Last. Again Om is said to be the first and last of all things, because, says Táránátha, every thing proceeds from its centre as its source, and returns to that centre as its reservoir. तस्मान्निःसृताः सर्व्वेप्रलीयन्त तत्रबै । वाचस्पत्याभिधानं; or that every thing like the line of the circle meets at the same point from where it is drawn and stretched. Moreover Om as has been already said, is used both as the initial and final word of Mantras and prayers, so it is understood to be the beginning and end of all motions and utterances. In these senses it answers the Alpha and Omega of the Revelation, and the initium and finem—Hoal awl Hoal ákher of the Koran.
10. The First, Last and Midst. आद्यन्त मध्यं । But Om is declared again to be the first, last and midst of things, from its being uttered in the beginning, middle and end of prayers and recitals of sacred hymns according to the ordinance which says that, Om is to be repeated thrice at every recital in the beginning, middle and end:—प्रशस्तं ब्राह्मणे नित्यं प्रणवत्रय संयुतं । मध्येच प्रणवं गुप्तंचाकारानुमं प्रिये । इति गायत्री तन्त्रं । This rule is said to bear reference to the triple state of the progression of mortal beings,—their evolution, sustentation and dissolution. यतोबाइमानि भूतानि जायन्ते येन जातानि । जीबन्ति यत् प्रयन्त्यभिसम्बिशन्ति तद्ब्र्ह्मेति ॥ The triple utterance of Om has given rise to the triplicate invocation of Hari, आदाबन्तेच मध्येच हरिः सर्ब्बत्र गीयते, and with what Milton has expressed in his glorious hymn in the Paradise Lost.
“Him first, Him last, Him midst, and without end.”
The reverend Gaudapáda enjoins the same ordinance in his versified commentary or Káriká to the Mándukya Upanishad, where he says (verse 27):—सर्ब्बस्य प्रणबो ह्यादिर्मध्यमान्तस्तथैबच । एवं हि प्रणवं ज्ञात्वा ब्यश्नुते तदनन्तरं ।