इति गुह्यतमं शास्त्रमिदमुक्तं मयाऽनघ। एतद्बुद्ध्वा बुद्धिमान्स्यात्कृतकृत्यश्च भारत ॥

iti guhyatamaṁ śhāstram idam uktaṁ mayānagha etad buddhvā buddhimān syāt kṛita-kṛityaśh cha bhārata

Thus by Me this most secret teaching hath been told O sinless one. This known, he hath become illuminated and hath finished his work, O Bhârata.

In plain words: Krishna tells Arjuna, whom he calls pure, that he has now shared this most secret teaching. Whoever understands it becomes wise and has done what life is for.