Bhagavad Gita 15.20 Chapter 15, Verse 20

इति गुह्यतमं शास्त्रमिदमुक्तं मयाऽनघ ।
एतद्बुद्ध्वा बुद्धिमान्स्यात्कृतकृत्यश्च भारत ॥१५.२०॥

iti guhyatamaṃ śāstramidamuktaṃ mayā'nagha
etadbuddhvā buddhimānsyātkṛtakṛtyaśca bhārata

Meaning

Thus, O sinless one, I have taught this most secret teaching. Understanding it, a person becomes wise and fulfilled, O Bharata.

Newly written by Bhajan Dhun — scholarly review in progress.

Reference: Bhagavad Gita 15.20 (Chapter 15, The Yoga of the Supreme Person (Purushottama Yoga), Verse 20)