Thus this most secret thing, the most hidden, the utterly secret. What is it? The scripture. Although the whole scripture named the Gītā is called scripture, still this very chapter is here called 'scripture', for the sake of praise, by reason of the topic; for the whole meaning of the scripture of the Gītā has been told in brief in this chapter. And not only the meaning of the scripture of the Gītā; the whole meaning of the Veda too is rounded off here, for it was said 'he who knows that is a knower of the Veda' (Gītā 15.1) and 'by all the Vedas I alone am the thing to be known' (Gītā 15.15). This has been told, declared, by Me, O sinless one. Having understood this scripture, of the matter shown, one would become possessed of understanding, of good understanding, and not otherwise; and one who has done what was to be done, O Bhārata: whatever is to be done by the brāhmaṇa born of a distinguished birth, all of it is done when the truth of the Blessed Lord is known, and the thing to be done is for no one rounded off otherwise. So it was said, 'all action, without remainder, O Pārtha, is completed in knowledge' (Gītā 4.33); and so too the word of Manu, 'this is the fullness of birth, especially for the brāhmaṇa; for, having reached this, the twice-born becomes one who has done what was to be done, and not otherwise' (Manu-smṛti 12.93). Since you have heard this supreme-truth reality from Me, you are fulfilled, O Bhārata. Thus ends the fifteenth chapter in the commentary on the Bhagavad Gītā composed by the most reverend Śaṅkara the Blessed, pupil of the most reverend Govinda the Blessed whose feet are worthy of worship, the venerable wandering ascetic of the supreme order.
Contemporary English rendering of the Sanskrit bhāṣya, pending scholar review.