Mandukya Karika, verse 4.13

Text

अजाद्वै जायते यस्य दृष्टान्तस्तस्य नास्ति वै ।
जाताच्च जायामानस्य न व्यवस्था प्रसज्यते ॥ १३ ॥

ajādvai jāyate yasya dṛṣṭāntastasya nāsti vai |
jātācca jāyāmānasya na vyavasthā prasajyate || 13 ||

13. There is no illustration to support the view of him who says that the effect is born from the unborn cause. Again, if it be said that the effect is produced from a cause which is itself born then it leads to a regressus ad infinitum.

Shankara Bhashya (commentary)

Moreover, the disputant1 who says that the effect is produced from an unborn cause, cannot furnish an illustration to support his view. In other words, it is consequently established that nothing is born from an unborn cause as there is no illustration to support this view. If,2 on the other hand, it be contended that the effect is born from a born cause, then that cause must be born from some other born cause and so on, which position never enables us to reach a cause which is, in itself, unborn. In other words, we are faced with an infinite regress.