Passage
Taittiriya Upanisad TaittU_2,6.1
san taittiriya
asanneva sa bhavati asad brahmeti veda cet / asti brahmeti cedveda santamenaṃ tato viduriti / tasyaiṣa eva śārīra ātmā yaḥ pūrvasya / athāto 'nupraśnāḥ / utāvidvān amuṃ lokaṃ pretya kaścana gacchatī3 / āho vidvānamuṃ lokaṃ pretya kaścitsamaśnutā3 u / so 'kāmayata / bahu syāṃ prajāyeyeti / sa tapo 'tapyata / sa tapastaptvā idaṃ sarvamasṛjata yadidaṃ kiñca / tatsṛṣṭvā tadevānuprāviśat / tadanupraviśya sacca tyaccābhavat / niruktaṃ cāniruktaṃ ca nilayanaṃ cānilayanaṃ ca vijñānaṃ cāvijñānaṃ ca satyaṃ cānṛtaṃ ca / satyamabhavat yadidaṃ kiñca / tatsatyam ityācakṣate / tadapyeṣa śloko bhavati