Mandukya Karika, verse 3.26

Text

स एष नेति नेतीति व्याख्यातं निह्नुते यतः ।
सर्वमग्राह्यभावेन हेतुनाजं प्रकाशते ॥ २६ ॥

sa eṣa neti netīti vyākhyātaṃ nihnute yataḥ |
sarvamagrāhyabhāvena hetunājaṃ prakāśate || 26 ||

26. As the Śruti passage, “It is not this, not this” on account of the incomprehensibility of Ātman, negates all (dualistic) ideas described; (as the means for the attainment of Ātman), therefore the birthless (Ātman alone) exists (and not any duality).

Shankara Bhashya (commentary)

The Śruti 1 in such passage as, “This is the final instruction. It is not this, not this,” has determined the nature of Ātman by the refutation of all specific characteristics. But knowing this Ātman to be incomprehensible2 the Śruti has again sought to establish the very same Ātman through other means and finally refuted what have been described (as the means for the attainment of Ātman). That is to say, the Śruti, in such passage as, “It is not this, not this,” demonstrates the incomprehensibility of Ātman or in other words, refutes the idea that Ātman 3 can be realised or understood. Those4 who do not understand that the means (suggested for the realisation of Ātman) have only one purpose, viz., the realisation of the end (i.e., the non-dual Ātman), make a mistake by thinking that what are suggested as the means have the same reality as the end. In order to remove this error, the Śruti negates the reality5 of the means by6 pointing out the incomprehensibility of Ātman, as its reason. Subsequently,7 the student knows that the means serve their purpose by pointing only to the end and the end itself is always one and changeless. To such a student the knowledge of the unborn Self which is both within and without reveals itself.8