This marks the beginning of Krishna’s description of the most confidential knowledge. Although there is a thematic similarity between chapter 9 and chapter 7, owing to dealing with pure unalloyed devotional service (bhakti), chapter 9 is being referred to as the most confidential.

Unto Arjuna, who is non-envious (anasūyave), Krishna will reveal the greatest mystery (guhya-tamaṁ), the most confidential (guhya-tamaṁ) knowledge (jñānaṁ) along with realization and wisdom (vijñāna-sahitaṁ), knowing which (yaj jñātvā) he will be liberated (mokṣyase) from all misfortune and miseries (aśubhāt). (BG 9.1) For further clarity on knowledge and realization, please refer to a previous discussion in chapter 7.

This (idam) is the king of education (rāja-vidyā), the king of all mysteries (rāja-guhyaṁ), and supremely (uttamam) pure (pavitram) or supreme (uttamam) purifier (pavitram). Realized by direct perception (pratyakṣāvagamaṁ), it is the righteous path (dharmyaṁ). It is very joyful to practice (su-sukhaṁ kartum) and everlasting (avyayam). (BG 9.2) The people (puruṣā) who don’t have faith (aśraddadhānāḥ) in this righteous path (dharmasyāsya) cannot attain (aprāpya) Krishna (māṁ) and will fall back (nivartante) to the path (vartmani) of birth and death in this material world (mṛtyu-saṁsāra). (BG 9.3)

Because Krishna is going to reveal the biggest transcendental mystery of all mysteries, we will require faith to access it. Note that continuing on from chapter 8, the focus is still on attaining Krishna and not returning back to this material world.