Chandogya Upanishad 8.1.4

8.1.4

taṃ ced brūyur asmiṃś cedaṃ brahmapure sarvaṃ samāhitaṃ sarvāṇi ca bhūtāni sarve ca kāmā yad enaj jarā vāpnoti pradhvaṃsate vā kiṃ tato 'tiśiṣyata iti \\801.4\

4. If they should say to him: ‘If within this city of Brahma is contained everything here, all beings as well as all desires, when old age overtakes it or it perishes, what is left over therefrom?’ he should say: ‘That does not grow old with one’s old age; it is not slain with one’s murder. That is the real city of Brahma. In it desires are contained. That is the Soul (Ātman), free from evil, ageless, deathless, sorrowless, hungerless, thirstless, whose desire is the Real, whose conception is the Real.