Bhagavad Gita · 13.35

क्षेत्रक्षेत्रज्ञयोरेवमन्तरं ज्ञानचक्षुषा।भूतप्रकृतिमोक्षं च ये विदुर्यान्ति ते परम्॥

kṣhetra-kṣhetrajñayor evam antaraṁ jñāna-chakṣhuṣhā bhūta-prakṛti-mokṣhaṁ cha ye vidur yānti te param

Those who thus perceive, with the eye of knowledge, the difference between the field and the knower of the field, and the liberation of beings from material nature — they attain the Supreme.

— Bhagavad Gita 13.35

Source: Sacred-Texts.com (Sanskrit) + Bhagavad-Gita.io (translations)