Meaning
Supreme God Krishna spoke
{Sacrificial} Karmas (duties) originate in the Vedas, which in turn have their source in the Imperishable Absolute. Therefore, the All-pervasive Brahm (the Formless God) is always present in the yajna {said Brahmā}. (3:15)
Sanskrit
श्रीभगवान् उवाच
कर्म ब्रह्मोद्भवं विद्धि ब्रह्माक्षरसमुद्भवम् ।
तस्मात्सर्वगतं ब्रह्म नित्यं यज्ञे प्रतिष्ठितम्॥
Word-by-word
कर्म ब्रह्म-उद्भवम् विद्धि ब्रह्म अक्षर-समुद्भवम्।
तस्मात् सर्व-गतम् ब्रह्म नित्यम् यज्ञे प्र-तिष्ठितम्।।
Commentary
The word “Brahm” is used three times in the verse. This word’s dictionary meanings include both “Vedas” and the “Formless, Indeterminate God.” The third occurrence of “Brahm” in the verse is interpreted as “God” because the adjective “all-pervasive” precedes it. It is once again reminded that verses 3:10 to 15 are reporting what Semi-God Brahmā said when he created the world and the humans, and these are not the views of God-the-Supreme represented by Bhagawān Krishna.
From verse 3:16, Bhagawān Krishna starts gently and subtly sidelining what was said by Brahmā in verses 3:10-15. Bhagawān Krishna has no high praise for the Vedas. In the Holy Gitā, he has repeatedly highlighted the limitations of the Vedas (2:42-46, 53; 9:20-25; 11:53), which originated from the mouth of Semi-God Brahmā according to the Bhāgawata Purāna. This Purāna is a relatively a more reliable scripture to explain the verses and words of the Holy Gitā. After the arrival of the Holy Gitā, the Holy Gitā became the highest Scripture, being the direct Word of God. Look at Ch. 24 of the 10th Skandha of this allied scripture, the Bhāgawata Purāna. We find Bhagawān Krishna persuading his father and the villagers not to go for the yajna, meant to appease the Vedic god Indra, who was supposed to bring rains. In verses 13-17 of Ch. 24, Tenth Skandha of the Bhāgawata Purāna, Bhagawān Krishna explains at length that for a good life, what is more important is the right endeavors of men and women, and, instead of bothering the gods, men and women should shape their destiny with their own hands.