Passage
Taittiriya Upanisad TaittU_2,9.1
san taittiriya
yato vāco nivartante aprāpya manasā saha / ānandaṃ brahmaṇo vidvān na bibheti kutaścaneti / etaṃ ha vāva na tapati / kimahaṃ sādhu nākaravam / kimahaṃ pāpamakaravamiti / sa ya evaṃ vidvānete ātmānaṃ spṛṇute / ubhe hyevaiṣa ete ātmānaṃ spṛṇute ya evaṃ veda / ityupaniṣat