Chapter 18 · Liberation through Renunciation · Krishna said
Bhagavad Gita 18.64 — The most secret word
सर्वगुह्यतमं भूयः शृणु मे परमं वचः। इष्टोऽसि मे दृढमिति ततो वक्ष्यामि ते हितम् ॥
sarvaguhyatamaṃ bhūyaḥ śṛṇu me paramaṃ vacaḥ | iṣṭo'si me dṛḍhamiti tato vakṣyāmi te hitam ||
Meaning
Hear once more My highest word, the most secret of all. You are very dear to Me, so I tell you what is truly good for you.