तस्मादोमित्युदाहृत्य यज्ञदानतपःक्रियाः।प्रवर्तन्ते विधानोक्ताः सततं ब्रह्मवादिनाम्।।17.24।।
tasmād oṁ ity udāhṛitya yajña-dāna-tapaḥ-kriyāḥ pravartante vidhānoktāḥ satataṁ brahma-vādinām
Therefore, with the utterance of "Om," the acts of sacrifice, gift, and austerity, as enjoined in the scriptures, are always begun by the students of Brahman.