योगवासिष्ठः yogavāsiṣṭhaḥ - book-7, chapter-63, verse-24

ते स्वप्नपुरुषास्तेषां सत्या एवानुभूतितः ।
आत्मनोऽपि परस्यापि सर्वगत्वाच्चिदात्मनः ॥ २४ ॥

te svapnapuruṣāsteṣāṃ satyā evānubhūtitaḥ ,
ātmano'pi parasyāpi sarvagatvāccidātmanaḥ 24

24. As other people have the notion of their existence from their reminiscence alone, so have we of ourselves and theirs also, from the ubiquious nature or omnipresence of the intellectual soul.