Kaṭha Upaniṣad 246

246

yathādarśe pratibimbabhūtam ātmānaṃ paśyati loko 'tyantaviviktam, tathehātmani svabuddhāvādarśavan nirmalībhūtāyāṃ viviktam ātmano darśanaṃ bhavatīty arthaḥ / yathā svapne 'viviktaṃ jāgradvāsanodbhūtam, tathā pitṛloke 'viviktam eva darśanam ātmanaḥ karmaphalopabhogāsaktatvāt / yathā cāpsv aviviktāvayavam ātmarūpaṃ parīva dadṛśe paridṛśyata iva, tathā gandharvaloke 'viviktam eva darśanam ātmanaḥ / evañ ca lokāntareṣv api śāstraprāmāṇyād avagamyate / chāyātapayor ivātyantaviviktaṃ brahmaloka evaikasmin / sa ca duṣprāpo 'tyantaviśiṣṭakarmajñānasādhyatvāt / tasmād ātmadarśanāyehaiva yatnaḥ kartavya ity abhiprāyaḥ ///2,3.5 //

Shankara’s Commentary:
Com.—How is explained. As one in the world sees his own image reflected in a mirror very distinctly, so the realisation of the atman in one's intelligence, when spotless like a mirror, becomes clear. As in dreams, the perception is indistinct and produced, i.e., (obscured) by the reminiscences of the waking state, so indistinct is the realisation of the atman in the world of the manes, being engrossed in the enjoyment of the fruits of karma. As the image of one's self reflected in water is seen indistinctly, with the various parts not defined, so is the realisation of the atman in the world of the Gandharvas certainly indistinct. Thus, it is inferred from the authority of the sastras, even in other worlds, it is only in one, the Brahmaloka, that it is very distinct, as that of light and shadow and that (Brahmaloka) is hard to attain requiring as means, a combination of very special karma and knowledge, i.e., (worship). The drift, therefore, is that one should attempt to realise the atman even while here (in this world).