Bhagavad Gita Chapter 13, Verse 29

प्रकृतिं यान्ति भूतानि निग्रहः किं करिष्यति | स्वभावजस्य कर्मणः साक्षी चास्मि निरङ्गकः ||

prakṛtiṁ yānti bhūtāni nigrahaḥ kiṁ kariṣyati svabhāva-jasya karmaṇaḥ sākṣī cāsmi niraṅgakaḥ

All beings go to material nature. What can restraint do? I am the witness of action born from nature, without attachment.

Krishna explains the nature of action and the role of the knower. 'Prakṛtiṁ yānti bhūtāni'—all beings go to material nature. All beings are part of material nature—they're part of the field. 'Nigrahaḥ kiṁ kariṣyati'—what can restraint do? You can't control material nature by force. The field operates according to its nature. 'Svabhāva-jasya karmaṇaḥ sākṣī cāsmi niraṅgakaḥ'—I am the witness of action born from nature, without attachment. The knower is the witness of the field's actions. The field acts according to its nature. The knower witnesses without attachment. When you understand this, you recognize that you can't control the field—it acts according to its nature. But you (the knower) are the witness—you observe without attachment. You don't need to control the field—you need to recognize you're the witness of it.