Bhagavad Gita Chapter 17 Verse 23
भगवद् गीता अध्याय 17 श्लोक 23

तत्सदिति निर्देशो ब्रह्मणस्त्रिविधः स्मृतः।
ब्राह्मणास्तेन वेदाश्च यज्ञाश्च विहिताः पुरा।।17.23।।



हिंदी अनुवाद - स्वामी तेजोमयानंद
।।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।।


Kumara Vaishnava Sampradaya - Commentary
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.