Bhagavad Gita Chapter 17 Verse 24 भगवद् गीता अध्याय 17 श्लोक 24 तस्मादोमित्युदाहृत्य यज्ञदानतपःक्रियाः। प्रवर्तन्ते विधानोक्ताः सततं ब्रह्मवादिनाम्।।17.24।। हिंदी अनुवाद - स्वामी रामसुख दास जी ( भगवद् गीता 17.24) ।।17.24।।इसलिये वैदिक सिद्धान्तोंको माननेवाले पुरुषोंकी शास्त्रविधिसे नियत यज्ञ? दान और तपरूप क्रियाएँ सदा इस परमात्माके नामका उच्चारण करके ही आरम्भ होती हैं। Rudra Vaishnava Sampradaya - Commentary 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 Vaishnava Sampradaya - Commentary 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. Shri Vaishnava Sampradaya - Commentary 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 Vaishnava Sampradaya - Commentary 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.