|Chapter 17||The Threefold Divisions of Material Existance||Verse 24|
Rudra Vaisnava Sampradaya:
In order to convey the supreme, eternal auspiciousness of OM TAT SAT, Lord Krishna first glorifies the pranava OM. Pranava from the root word prana meaning breath, refers to the first breath and is the sound of OM beginning all Vedic rites. In the performance of all Vedic rites such as yagna or propitiation, tapah or austerities and danam or charity; the pranava OM is always reverently vibrated as the first audible sound. The transcendental sound of OM is the personalised vibration of the Supreme Lord, it is most auspicious and eternal. By its transcendental potency all activities performed by the Vaisnavas and brahmanas enjoined by the ordinances of the Vedic scriptures are auspiciously begun with OM exclusively and by doing so insures that whatever may be defective becomes efficacious.
Brahma Vaisnava Sampradaya:
Once again the Supreme Lord Krishna describes the modalities of actions that are essential to be performed by revealing OM TAT SAT. These three divine syllables headed by the transcendental sound vibration OM are all verily nomenclatures of the Supreme Lord. All over creation the Supreme Lord pervades by His internal potency with the omnipresence of OM. As the Supreme Lord is glorified with the greatest respect in all the Vedic scriptures, He is known as TAT. Since the Supreme Lord is perfect without any defects and completely auspicious, He is known as SAT. The following information is confirmed in the Rig Veda: OM TAT SAT is vibrated for propitiation to the Supreme Lord, adherence to the Vedic ordinances and injunctions and honouring creation, the brahman or spiritual substratum pervading all existence and the atma or immortal soul within all jivas or embodied beings.
Sri Vaisnava Sampradaya:
Lord Krishna elaborates the ontology of OM TAT SAT and how they are interrelated. The words brahma-vadinam are those who follow the injunctions and ordinances of the Vedic scriptures and refers to the three higher varnas or castes beginning with the brahmins or priestly class, ksatriyas the royal and warrior class and vaisyas the merchant class. Yagna or propitiation and worship to the Supreme Lord is performed exclusively by the Vaisnavas and Brahmins. Tapah or austerities is performed by the Vaisnava brahmins and the ksatriyas. Danam or charity is performed by the ksatriyas and vaisyas and is offered to the Vaisnavas and brahmanas to be utilised for the service of the Supreme Lord Krishna or any of His avatars or authorised incarnations and expansions according to vedic scriptures. Thus the relationship between the three higher varnas has been clarified. All prescribed Vedic rituals must be performed exclusively by the Vaisnavas and brahmanas and always commence with the transcendental sound vibration OM. The Vedas begin with OM as well. Thus the eternal connection between OM and the Vedas and OM and yagnas has been demonstrated and firmly established as only in conjunction with the transcendental sound of OM at the commencement are the Vedas recited and the performance of yagnas is bonafide.
Kumara Vaisnava Sampradaya:
The transcendental evocation OM TAT SAT denotes the Supreme Lord Krishna through His abstract auxiliary potency the brahman or spiritual substratum pervading all existence and is all auspiciousness. Due to this interaction the recitation of OM TAT SAT by duly initiated Vaisnavas and brahmanas at the commencement of all Vedic rites insures success and is ascertained as the cause of accomplishing all Vedic rituals successfully causing well being and attainment to the Vaisnavas and brahmanas who are the topmost members of creation. Now in order to delineate the proper actions involved with each for achieving the desired goal, Lord Krishna begins with OM explaining that it is a name for the brahman and is a potency of the Supreme Lord as it is connected to the prime source of all the Vedic scriptures. Therefore by vibrating the transcendental pranava OM at the commencement of any prescribed Vedic activity without any pause or digression stabilises the continuity and connection insuring successful accomplishment of yagna or propitiation and worship by Vaisnavas and brahmanas, tapah or austerities by the ksatriyas or royal warrior class and danam or charity by the vaisyas or merchant class.