Bhagavatapurana 4.28.40

4.28.40

sa vyāpakatayātmānaṃ vyatiriktatayātmani /
vidvān svapna ivāmarśa- sākṣiṇaṃ virarāma ha //

40. Having realised in himself Atman as all pervading and as quite distinct (from everything else), like the witness of mental activities in a dream, he ceased (to percieve anything else as having an existence).