To him who has thus properly approached, of serene mind, endowed with tranquility, the sage instructs in that Brahma-vidyā by which he knows the immutable Person, the Real.

The transmission of higher knowledge requires preparation of the disciple.

Upasannāya — one who has approached. Not physically but with proper inner preparation.

Samyak — properly, completely. The correct attitude: reverence, humility, commitment.

Praśānta-cittāya — of serene mind. Tranquility as a requirement; knowledge flows where there is calm.

Śamānvitāya — endowed with tranquility. Śama as the first of spiritual qualities.

Akṣaraṃ puruṣaṃ — the immutable Person. That which never exhausts, that which never changes.

Tattvataḥ — in reality, truly. Not theoretically but as lived reality.

Brahma-vidyām — the knowledge of Brahman. The theme of the second muṇḍaka.

The teacher transmits what cannot be grasped by the senses nor understood by discursive mind.