Mandukya Karika, verse 4.55

Sanskrit text, IAST transliteration and English translation

यावद्धेतुफलावेशस्तावद्धेतुफलोद्भवः ।
क्षीणे हेतुफलावेशे नास्ति हेतुफलोद्भवः ॥ ५५ ॥

yāvaddhetuphalāveśastāvaddhetuphalodbhavaḥ |
kṣīṇe hetuphalāveśe nāsti hetuphalodbhavaḥ || 55 ||

55. As long as a man persists in the belief in causality he will find the working of cause and effect. But when attachment to causality vanishes, cause and effect become non-existent.

Shankara Bhashya (commentary)

What happens with regard to those who cling to the belief in cause and effect? In reply, it is said:—As long as there is faith in causality, as long as a man thinks, “I am the agent; these virtuous and vicious deeds belong to me. I shall enjoy the results of these actions, being born in course of time, as some being,” in other words, as long as a man falsely attributes causality to Ātman and devotes his mind to it, cause and effect must operate for him; that is to say, the man must without intermission be subject to birth and death, which are the result of his attachment to the belief in causality. But when attachment to causality, due to ignorance, is destroyed by the knowledge of non-duality as described above,—like the destruction of the possession of a ghost through the power of incantation, medicinal herb, etc.—then on account of the wearing away of the illusion of causality, do cause and effect cease to exist.

Anandagiri Tika (glossary)

This Kārikā tells us that the chief duty of the student is to analyse the law of causality and find its illusory nature. The attainment of true knowledge solely depends upon this understanding of the causal law.