parāñci khāni vyatṛṇat svayambhūs
tasmāt parāṅ paśyati nāntarātman |
kaś cid dhīrah pratyagātmānam aikṣad
āvṛttacakṣur amṛtattvam icchan ||
The self born creator bored the sense openings outwards,
so the self looks out at the world rather than inwards.
A wise person, wanting to taste the state of immortality,
stops the senses from moving outwards and turns within to the essence.
Kaṭha Upaniṣaṭ 2.1.1.