Bṛhadāraṇyaka Upaniṣad ("Great Forest Teaching") 4.4.22

4.4.22

sa vā eṣa mahānaja ātmā yo'yaṃ vijñānamayaḥ prāṇeṣu ya eṣo'ntarhṛdaya ākāśastasmiñchetesarvasya vaśī sarvasyeśānaḥ sarvasyādhipatiḥ sa na sādhunā karmaṇā bhūyānno evāsādhunā kanīyāneṣa sarveśvara eṣa bhūtādhipatireṣa bhūtapāla eṣa seturvidharaṇa eṣāṃ lokānāmasaṃbhedāya tametaṃ vedānuvacanena brāhmaṇā vividiṣanti yajñena dānena tapasānāśakenaitameva viditvā munirbhavati etameva pravrā-jinolokamicchantaḥ pravrrajanti | etaddha sma va aitatpūrve vidvām̐saḥ prajāṃ na kāmayanti kiṃ prajayā kariṣyāmo yeṣāṃ no'yamātmāyaṃ loka iti te ha sma putraiṣaṇāyāśca vittaiṣaṇāyāśca lokaiṣaṇāyāśca vyutthāyātha bhikṣācaryaṃ caranti yā hyeva putraiṣaṇā sā vittaiṣaṇā yā vittaiṣaṇā sā lokaiṣaṇome hmete eṣaṇe eva bhavataḥ | sa eṣa neti netyātmāgṛhyo na hi gṛhyate'śīryo na hi śīryate'saṅgo na hi sajyate'sito na vyathate na riṣyatyetamu haivaite na tarata ityataḥ pāpamakaravamityataḥ kalyāṇa-makaravamityubhe u haivaiṣa ete tarati nainaṃ kṛtākṛte tapataḥ

'And he is that great unborn Self, who consists of knowledge, is surrounded by the Prânas, the ether within the heart. In it there reposes the ruler of all, the lord of all, the king of all. He does not become greater by good works, nor smaller by evil works. He is the lord of all, the king of all things, the protector of all things. He is a bank and a boundary, so that these worlds may not be confounded. Brâhmanas seek to know him by the study of the Veda, by sacrifice, by gifts, by penance, by fasting, and he who knows him, becomes a Muni. Wishing for that world (for Brahman) only, mendicants leave their homes.
'Knowing this, the people of old did not wish for offspring. What shall we do with offspring, they said, we who have this Self and this world (of Brahman)? And they, having risen above the desire for sons, wealth, and new worlds, wander about as mendicants. For desire for sons is desire for wealth, and desire for wealth is desire for worlds. Both these are indeed desires only. He, the Self, is to be described by No, no! He is incomprehensible, for he cannot be comprehended; he is imperishable, for he cannot perish; he is unattached, for he does not attach himself; unfettered, he does not suffer, he does not fail. Him (who knows), these two do not overcome, whether he says that for some reason he has done evil, or for some reason he has done good--he overcomes both, and neither what he has done, nor what he has omitted to do, burns (affects) him.