1 Gita Sloka Every Day - Chapter 17 - Shraddhatraya Vibhaga Yoga - Sloka 24

The entire content of this mail is from Shri V N Gopala Desikan's  Srimad Bhagavad Gita, published by Vishishtadvaita Research Centre, Chennai and The Bhagavad Gita by Swami Chidbhavananda published by Ramakrishna Mission

Demerits Turned into Merits 23-28

1 Gita Sloka  Every Day - Chapter 17 - Shraddhatraya Vibhaga Yoga - Sloka 24

Tasmad aum ity udahrtya yajna dana tapah kriyah

Pravartante vidhanoktah satatam brahmavadinam  sloka 24

तस्मात् ॐ इति उदाह्र्त्य यज्ञ दान तपः क्रियः I 
प्रवर्तन्ते विधानोक्तः सततं ब्रह्म वादिनं II  श्लोक 24

Therefore, with the utterance of "Om", are the acts of sacrifice, gift and austerity, as enjoined in the scriptures, always undertaken by the followers of the Vedas. 

There is no karma which is all perfect. For that reason no karma can be dropped out. Any attempt by the embodied to eschew karma proves futile. A karma is therefore commenced with the utterance "Om" in order to eradicate the evil in it. The implication is that every karma ought to be in accordance with the plan of Nature. There is a divine orderliness in the working of Nature; and it aids the evolution of the Jivatman. Every karma done by man ought to aid his divine purpose. This principle has in course of time, modified itself onto the worship of Ganesha, who is also known as Vigneswara or the Lord who wards off obstacles. This Deity is the embodiment of "Om". As all sounds merge in "Om" all actions ought to be in harmony with the cosmic scheme. That karma alone is performed successfully which fulfills this condition. This is the infallible law governing the idea that a karma ought to be commenced after uttering "Om".