तत्सदिति निर्देशो ब्रह्मणस्त्रिविधः स्मृतः।
ब्राह्मणास्तेन वेदाश्च यज्ञाश्च विहिताः पुरा।।17.23।।
।।17.23।। ? तत् सत् ऐसा यह ब्रह्म का त्रिविध निर्देश (नाम) कहा गया है उसी से आदिकाल में (पुरा) ब्राहम्ण? वेद और यज्ञ निर्मित हुए हैं।।
Up until this time Lord Krishna has elaborated upon the distinctions between yagna or propitiation, tapah or austerities and dana or charity and how they are categorised in the three gunas or modes of material nature. Now the Supreme Lord will illustrate how yagna, tapah and dana become spiritualised by being unified with the pranava OM. The term pranava refers to first breath which is first vibrated as OM commencing all Vedic rites. It is derived from the root word prana meaning breath and is properly pronounced AAH with mouth open OOH with lips puckered and MMMM by pursing them together. The triplicate formula OM TAT SAT is used in reference to the brahman or spiritual substratum pervading all existence which is the impersonal aspect of the Supreme Lord. The brahman also refers to the Vedas which also originally emanated from the Supreme Lords prana. The Vedas denote Vedically ordained activities of which yagna, tapah and dana are essential. All Vedically ordained yagnas, rituals and ceremonies are only bonafide and valid if prefaced with the pranava OM at its commencement accompanied by its auxiliaries TAT and SAT. The absence of the transcendental sound of OM vibrating from the very inception of any Vedic activity automatically disqualifies it and renders it invalid even if subsequent rituals are performed perfect and perfunctory. The pranava OM is an eternal prerequisite for every expiatory rite prescribed in the Vedic scriptures and thus indispensable. The pranava OM is the transcendental sound vibration personally representing the Supreme Lord Krishna. The auxiliary TAT denotes complete perfection and auspiciousness and the auxiliary SAT denotes the source of all creation. The Vaisnavas and the brahmanas are those who have the sole right and exclusive authority to vibrate these transcendental sound vibrations audibly and inaudibly during all rituals prescribed in the Vedic scriptures. Brahmanas are those seminally born in India in the topmost caste of Brahmin families. Vaisnavas are devotees of the Supreme Lord Krishna or any of His authorised incarnations and expansions as revealed in Vedic scriptures, who are born in any caste, in any country, in any planetary system and who are so attracted to the Supreme Lord Krishna that they make themselves available to receive twice born Brahmin initiation from a Vaisnava acarya or bonafide spiritual master from one of the four authorised sampradaya or bonafide channel of disciplic succession. Only duly initiated Vaisnavas and Brahmins are ordained to perform Vedic rites, no others have this authority and in this matter there is no exception. The Brahmins and the Vaisnavas were originally created by the Supreme Lord along with the Vedas and yagnas to harmoniously evolve and perfect all creation.