Taittirīya Upaniṣad 2.9

2.9.1

yato vāco nivartante /
aprāpya manasā saha /
ānandaṃ brahmaṇo vidvān /
na bibheti kutaścaneti /
etam̐ ha vāva na tapati /
kimaham̐ sādhu nākaravam /
kimahaṃ pāpamakaravamiti /
sa ya evaṃ vidvānete ātmānam̐ spṛṇute /
ubhe hyevaiṣa ete ātmānam̐ spṛṇute /
ya evaṃ veda /
ityupaniṣat // 1//
iti navamo 'nuvākaḥ //
iti brahmānandavallī samāptā //

Wherefrom words turn back,
Together with the mind, not having attained—
The bliss of Brahma he who knows,
Fears not from anything at all.

Such a one, verily, the thought does not torment: ‘Why have I not done the good (_sādhu_)? Why have I done the evil (_pāpa_)?’ He who knows this, saves (_spṛṇute_) himself (_ātmānam_) from these [thoughts]. For truly, from both of these he saves himself—he who knows this!

Such is the mystic doctrine (_upaniṣad_)!