तत्सदिति निर्देशो ब्रह्मणस्त्रिविधः स्मृतः।ब्राह्मणास्तेन वेदाश्च यज्ञाश्च विहिताः पुरा।।17.23।।
तस्मादोमित्युदाहृत्य यज्ञदानतपःक्रियाः।प्रवर्तन्ते विधानोक्ताः सततं ब्रह्मवादिनाम्।।17.24।।
“Om-tat-sat” - this is considered to be the threefold designation of Brahman. The Brahmanas, Vedas, and sacrifices were ordained by that in days of yore.
Therefore, acts of sacrifice, charity, and austerity, as prescribed through injunctions, of those who study and expound the Vedas, always commence after uttering the syllable ‘Om’.
Osho’s Commentary
Krishna now gives the supreme, triple formula: Om Tat Sat. This is the triple name of the ultimate reality, of Brahman. Om is the primordial sound, the uncaused vibration of existence itself. To begin every sacred act with the utterance of Om is to align yourself with the cosmic harmony. Tat means “That,” pointing to the ultimate, transcendental reality that is beyond all name and form. Sat means “the real,” “the good,” that which truly is. These three words contain the entire essence of the spiritual journey. They are not just words, but potent vibrations that can transform your consciousness.