|Chapter 17, Verse 24|

तस्मादोमित्युदाहृत्य यज्ञदानतपःक्रियाः।प्रवर्तन्ते विधानोक्ताः सततं ब्रह्मवादिनाम्।।17.24।।

ॐ

Transliteration / Meaning

tasmād oṁ ity udāhṛitya yajña-dāna-tapaḥ-kriyāḥ
pravartante vidhānoktāḥ satataṁ brahma-vādinām

Translation

Therefore, transcendentalists undertaking performances of sacrifice, charity and penance in accordance with scriptural regulations begin always with om, to attain the Supreme.

Purport by Srila Prabhupada

Om tad vishnoh paramam padam (Rig Veda 1.22.20). The lotus feet of Vishnu are the supreme devotional platform. The performance of everything on behalf of the Supreme Personality of Godhead assures the perfection of all activity.