The Katha Upanishad with Shankara’s Commentary
यस्त्वविज्ञानवान्भवत्यमनस्कः सदाऽशुचिः ।
न स तत्पदमाप्नोति सँ सारं चाधिगच्छति ॥ ७ ॥
yastvavijñānavānbhavatyamanaskaḥ sadā'śuciḥ ।
na sa tatpadamāpnoti sam̐ sāraṃ cādhigacchati ॥ 7 ॥
7. But he, whose intellect has no discrimination and whose thind is not under control and who is always unclean, does not reach that goal and falls into Samsâra.
Com.—Now the text mentions the results produced by the driver (intelligence) who is unknowing, as above stated; the lord of the chariot, who does not know and who has not the mind under control and who is, therefore, always unclean, does not attain that immortal great goal already described, by reason of having such a driver. It is not alone that he does not attain that, but he reaches Samsâra marked by births and deaths.