Mandukya Karika, verse 3.21-22

Sanskrit text, IAST transliteration and English translation

न भवत्यमृतं मर्त्यं न मर्त्यममृतं तथा ।
प्रकृतेरन्यथाभावो न कथंचिद्भविष्यति ॥ २१ ॥

na bhavatyamṛtaṃ martyaṃ na martyamamṛtaṃ tathā |
prakṛteranyathābhāvo na kathaṃcidbhaviṣyati || 21 ||

21. The immortal cannot become mortal, nor can the mortal ever become immortal. For, it is never possible for a thing to change its nature.

Shankara Bhashya (commentary)

As in common experience the immortal never becomes mortal, nor the mortal ever becomes immortal; therefore it is, in no way, possible for a thing to reverse its nature, i.e., to become otherwise than what it is. Fire can never change its character of being hot.

Verse 3.22

Sanskrit text, IAST transliteration and English translation

स्वभावेनामृतो यस्य भावो गच्छति मर्त्यताम् ।
कृतकेनामृतस्तस्य कथं स्थास्यति निश्चलः ॥ २२ ॥

svabhāvenāmṛto yasya bhāvo gacchati martyatām |
kṛtakenāmṛtastasya kathaṃ sthāsyati niścalaḥ || 22 ||

22. How can he, who believes that the naturally immortal entity becomes mortal, maintain that the Immortal, after passing through change, retains its changeless nature?

Shankara Bhashya (commentary)

The disputant who maintains that the naturally immortal entity becomes mortal, i.e., really passes into birth, makes¹ the futile proposition that that entity before creation is by its very nature, immortal. How can he assert that the entity is of immortal nature if it be admitted that it passes² into birth? That is to say, how can the immortal retain its immortal nature of changelessness if it should undergo a change? It cannot, by any means, be so. Those³ who hold that the Ātman passes into birth (i.e., undergoes a change), cannot speak of the Ātman as ever birthless. Everything, according to them, must be mortal. Hence⁴ there cannot be a state called liberation.

Anandagiri Tika (glossary)

It may be contended that Brahman, as the cause, is immortal before creation. But as effect, subsequent to the creation, it becomes mortal. Therefore there is no contradiction in associating with Brahman both immortal and mortal aspects which apply to its two states. This Kārikā refutes this contention.

¹ Makes, etc.—For, according to these disputes, the cause (i.e., Brahman), even before creation must contain within it the possibility of change; otherwise it cannot undergo a change. If this were admitted then the cause can no longer be called immortal.

² Passes, etc.—If an entity undergoes a change, that shows its impermanent characteristic inasmuch as it admits of the destruction of its inherent nature.

³ Those, etc.—The so-called Absolute of the dualists is also a mortal entity. For, nothing that passes through birth, can be immortal.

⁴ Hence, etc.—That is to say, Mukti or liberation in the sense of an immutable and permanent condition becomes an absurdity.