Sanskrit
तस्मादोमित्युदाहृत्य यज्ञदानतपःक्रियाः । प्रवर्तन्ते विधानोक्ताः सततं ब्रह्मवादिनाम् ॥
tasmād oṃ ity udāhṛtya yajñadānatapaḥkriyāḥ pravartante vidhānoktāḥ satataṃ brahmavādinām
Translation
Therefore with the pronunciation of "Aum" the acts of sacrifice, gift and austerity as laid down in the ordinances are always commenced by the knowers of the Eternal.
Annie Besant · The Bhagavad-Gita, translated by Annie Besant (4th ed., 1922) — Wikisource · Public Domain
Explanation
The first of three verses that each take one syllable of “Om Tat Sat” and explain its ritual function. Om marks the beginning: brahmavādins — “expounders of Brahman,” those who speak and act with the Absolute in view — open every prescribed act of sacrifice, gift, and austerity with it. It’s practical liturgy rather than abstract theology: a verbal gesture that reorients an ordinary ritual act toward the Absolute before the act itself even starts.