Bhagavad Gita Chapter 18, Verse 64

सर्वगुह्यतमं भूयः शृणु मे परमं वचः | इष्टोऽसि मे दृढमिति ततो वक्ष्यामि ते हितम् ||

sarvaguhyatamaṁ bhūyaḥ śṛṇu me paramaṁ vacaḥ iṣṭo 'si me dṛḍham iti tato vakṣyāmi te hitam

Hear again from Me the supreme word, the most secret of all. Since you are very dear to Me, therefore I will tell you what is beneficial for you.

Krishna prepares to reveal the most secret teaching. 'Sarvaguhyatamaṁ bhūyaḥ śṛṇu me paramaṁ vacaḥ'—hear (śṛṇu) again (bhūyaḥ) from Me (me) the supreme word (paramam vacaḥ), the most secret of all (sarva-guhyatamam). 'Iṣṭo 'si me dṛḍham iti tato vakṣyāmi te hitam'—since you are very dear (iṣṭaḥ asi me dṛḍham iti) to Me, therefore (tataḥ) I will tell (vakṣyāmi) to you (te) what is beneficial (hitam). This is the introduction to the most secret teaching: Krishna reveals that Arjuna is very dear to Him, and because of that, He will reveal the most beneficial teaching. This sets up the revelation of the ultimate secret—the final instruction that leads to liberation.