Muṇḍaka Upaniṣad · 2.2.8

मनोमयः प्राणशरीरनेता प्रतिष्ठितोऽन्ने हृदयं संनिधाय । तद्विज्ञानेन परिपश्यन्ति धीरा आनन्दरूपममृतं यद्विभाति

manomayaḥ prāṇa-śarīra-netā pratiṣṭhito'nne hṛdayaṃ saṃnidhāya | tad vijñānena paripaśyanti dhīrā ānanda-rūpam amṛtaṃ yad vibhāti

Made of mind, leader of the body of prāṇa, established in food, with the heart as seat — by the knowledge of that, the serene contemplate the form of bliss, the immortality that shines.

The Self in its subtle dimension: mind, energy, food, heart.

Manomayaḥ — made of mind. The mind as the subtlest layer of conditioned being.

Prāṇa-śarīra-netā — leader of the body of prāṇa. The governor of vitality.

Pratiṣṭhito’nne — established in food. The physical base, the dense that sustains the subtle.

Hṛdayaṃ saṃnidhāya — with the heart as seat. The heart as the throne of the Self.

Vijñānena — by knowledge, by wisdom. Not information but direct realization.

Dhīrāḥ — the serene, the firm. Those who have stabilized the mind.

Ānanda-rūpam — the form of bliss. Joy as the nature of the Self.

Amṛtaṃ vibhāti — the immortality that shines. The light that is life without end.