Bhagavad Gita Chapter 13, Verse 34

क्षेत्रक्षेत्रज्ञयोरेवमन्तरं ज्ञानचक्षुषा | भूतप्रकृतिमोक्षं च ये विदुर्यान्ति ते परम् ||

kṣetra-kṣetrajñayor evam antarṁ jñāna-cakṣuṣā bhūta-prakṛti-mokṣaṁ ca ye vidur yānti te param

Those who see with the eye of knowledge the distinction between the field and the knower of the field, and the liberation from material nature, attain the supreme.

Krishna summarizes the path to liberation. 'Kṣetra-kṣetrajñayor evam antarṁ jñāna-cakṣuṣā'—those who see with the eye of knowledge the distinction between the field and the knower. Understanding the distinction is seeing with the eye of knowledge—not physical sight, but the insight of understanding. 'Bhūta-prakṛti-mokṣaṁ ca ye vidur yānti te param'—and those who understand the liberation from material nature attain the supreme. When you understand the distinction between field and knower, and when you understand liberation from material nature (the field), you attain the supreme—Brahman, the ultimate reality. This is the culmination of Chapter 13's teaching: see the distinction, understand liberation, attain the supreme. The eye of knowledge sees what physical eyes cannot—the distinction between the temporary field and the eternal knower.