Verso 15.2015.115.215.315.415.515.615.715.815.915.1015.1115.1215.1315.1415.1515.1615.1715.1815.1915.20

Thus, this most secret science has been taught by Me, O sinless one; on knowing this, a man becomes wise, and all his duties are accomplished, O Arjuna.

Thus I have taught you this most secret teaching, sinless one. Understanding it, a person becomes wise and has done all that needs to be done, Bharata.

Krishna closes the chapter by calling this teaching the most secret of all, and addresses Arjuna as sinless, a sign of trust in his readiness to receive it. Whoever understands it becomes wise and kṛtakṛtya, one who has done all that needs doing. The claim is large: this short chapter is presented as a complete map, from the tree of worldly life, through the self that wanders in it, to the Supreme Person beyond it. The next chapter turns to the conduct that helps or hinders that journey.