however, seems to have been lost even at an early period of Sanskrit literature; for another is met with in the ancient grammarians, enabling us to account for the mysticism which many religious and theological works of ancient and medieval India suppose to inhere in it.  According to this latter etymology, Om would come from a radical av; by means of an affix man, when Om would be a curtailed form of avman or oman, and as av implies the notion of “protect, preserve, save,” Om would be a term implying “protection or salvation,” its mystical properties and its sanctity being inferred from its occurrence in the Vedic writings and in connection with sacrificial acts, such as are alluded to before.

Hence Om became the auspicious word with which the spiritual teacher had to begin and the pupil to end each lesson of his reading of the Veda.

“Let this syllable,” the existing Prati-sakhya, or a grammar of the Rig Veda, enjoins, “be the head of the reading of the Veda; for alike to the teacher and the pupil it is the supreme Brahman, the gate of heaven.”  And Manu ordains:  “A Brahman at the beginning and end (of a lesson on the Veda) must always pronounce the syllable Om; for unless Om precede, his learning will slip away from him; and unless it follows, nothing will be long retained.”

At the time when another class of writings (the Puranas) were added to the inspired code of Hinduism, for a similar reason Om is their introductory word.

That the mysterious power which, as the foregoing quotation from the law-book of Manu shows, was attributed to this word must have been the subject of early speculation, is obvious enough.  A reason assigned for it is given by Manu himself.  “Brahma,” he says, “extracted from the three Vedas the letter a, the letter u, and the letter m (which combined result in Om), together with the (mysterious) words Bhuh (earth), Bhuva (sky), and Swah (heaven);” and in another verse:  “These three great immutable words, preceded by the syllable Om, and (the sacred Rig Veda verse called) Gayatri, consisting of three lines, must be considered as the mouth (or entrance) of Brahman (the Veda),” or, as the commentators observe, the means of attaining final emancipation; and “The syllable Om is the supreme Brahman. (Three) regulated breathings, accompanied with the mental recitation of Om, the three mysterious words Bhuh, Bhuvah, Swah and the Gayatri, are the highest devotion.”

“All rites ordained in the Veda, such as burnt and other sacrifices, pass away, but the syllable Om must be considered as imperishable; for it is (a symbol of) Brahman (the supreme spirit) himself, the Lord of Creation.”  In these speculations Manu bears out, and is borne out by, several Upanishads.  In the Katha-Upanishad for instance, Yama, the god of death, in replying to a question of Nachiketas, says:  “The word which all the Vedas record, which all the modes of penance proclaim, desirous of which religious students perform their duties, this