Verse 1.13

द्वैतस्याग्रहणं तुल्यमुभयोः प्राज्ञतुर्ययोः ।
बीजनिद्रायुतः प्राज्ञः सा च तुर्ये न विद्यते ॥ १३ ॥

dvaitasyāgrahaṇaṃ tulyamubhayoḥ prājñaturyayoḥ |
bījanidrāyutaḥ prājñaḥ sā ca turye na vidyate || 13 ||

It means , “Dvaitam” a separate reality or Error is not seen by the ” prājñaḥ ” the deep sleeper and “Turiya” the pure consciousness. But, the ” prājñaḥ ” or the one who is in deep sleep is associated to Nidra (i.e Ignorance / blankness), where as, “Turiya” doesnot have ignorance (or deep sleep blankness) .

” prājñaḥ ” donot see dvaita (seperate reality) niether turiya see any seperate reality apart from it . But , ” prājñaḥ ” is covered in darnkness or blankness of deep sleep whereas , Turiya illumines everything!

Verse 1.13 mantra 7th, mandukya upanishad