Mandukya Karika, verse 4.21

Text

पूर्वापरापरिज्ञानम् अजातेः परिदीपकम् ।
जायमानाद्धि वै धर्मात् कथं पूर्वं न गृह्यते ॥ २१ ॥

pūrvāparāparijñānam ajāteḥ paridīpakam |
jāyamānāddhi vai dharmāt kathaṃ pūrvaṃ na gṛhyate || 21 ||

21. The ignorance regarding the antecedence and the subsequence of the cause and the effect clearly proves the absence of evolution or creation. If the effect (Dharma, i.e., the Jīva) has really been produced from a cause, then why can you not point out the antecedent cause?

Shankara Bhashya (commentary)

How do the wise assert the view of Ajāti or absolute non-evolution? It is thus replied:—The1 very fact that one does not know the antecedence and the subsequence of the cause and the effect is, in itself, the clearest indication of absolute non-evolution. If2 the effect (Dharma, i.e., the Jīva) be taken as produced (from a cause) then why cannot its antecedent cause be pointed out? It goes without saying that one who accepts birth as a fact must also know its antecedent cause. For, the relationship of the cause and the effect is inseparable and therefore cannot be given up Therefore the absence of knowledge (regarding the cause) clearly indicates the fact of absolute non-evolution.