Verses 8 & 9 are from the Bṛhadāraṇyaka Upaniṣad, which are the concluding verses about the origins of this Jagat in this text. It says, that before all this came into being, Jagat alone was, as an unmanifest potential. How then did the manifest come from the un-manifest? This is answered beautifully with the explanation of virāṭ and viśva.