Bhagavad Gita · Chapter 8: The Imperishable Absolute
Bhagavad Gita 8.20
परस्तस्मात्तु भावोऽन्योऽव्यक्तोऽव्यक्तात्सनातनः ।
यः स सर्वेषु भूतेषु नश्यत्सु न विनश्यति ॥
parastasmāttu bhāvo'nyo'vyakto'vyaktātsanātanaḥ | yaḥ sa sarveṣu bhūteṣu naśyatsu na vinaśyati ||
But beyond that unmanifest there is another, eternal unmanifest reality, which does not perish when all beings perish.
Modern context
There are two kinds of unmanifest. One is the dormant state into which the universe sleeps at night; it is still part of the cycle. Beyond it is another, eternal, which does not dissolve when everything dissolves. This is the ground that holds even the cosmic rhythm. Think of the silence in which music is played. The music starts and stops; the silence before and after is still there. The verse points to that deeper silence.