On Mundaka Upanishad: That which the self-knowers know

The following excerpt is from a samvaad (dialogue) session with Acharya Prashant.

हिरण्मये परे कोशे विरजं ब्रह्म निष्कलम् ।
तच्छुभ्रं ज्योतिषं ज्योतिस्तद्यदात्मविदो विदुः ॥

hiraṇmaye pare kośe virajaṃ brahma niṣkalam
tacchubhraṃ jyotiṣaṃ…