Kaṭha Upaniṣad 143

143

yas tu dvitīyo vijñānavān vījñānavat sārathyupeto rathī vidvān ity etat / yuktamanāḥ samanaskaḥ sa tata eva sadā śuciḥ, sa tu tatpadam āpnoti, yasmād āptāt padād apracyutaḥ san bhūyaḥ punar na jāyate saṃsāre ///1,3.8 //

Shankara’s Commentary:
Com.—But the second, i.e., the lord of the chariot who has a discriminating intellect as his driver, i.e., the knowing man, having his mind under control and being, therefore, always clean, reaches that goal from which never falling, he is not born again in Samsara.