Sanskrit
प्रकृतिं पुरुषं चैव क्षेत्रं क्षेत्रज्ञमेव च । एतद्वेदितुमिच्छामि ज्ञानं ज्ञेयं च केशव ॥
prakṛtiṃ puruṣaṃ caiva kṣetraṃ kṣetrajñam eva ca etad veditum icchāmi jñānaṃ jñeyaṃ ca keśava
Translation
Matter and Spirit, even the Field and the Knower of the Field, wisdom and that which ought to be known, these I fain would learn, O Keshava.
Annie Besant · The Bhagavad-Gita, translated by Annie Besant (4th ed., 1922) — Wikisource · Public Domain
Explanation
Arjuna’s question sets up the chapter’s entire vocabulary in a single line: prakriti (nature/matter), purusha (spirit/self), kshetra (the field), and kshetrajna (the knower of the field), plus a request for both jnana (wisdom) and jneya (its object). The four terms arrive as two pairs that turn out to name the same distinction from two angles — kshetra/kshetrajna is the epistemic pairing (what’s known vs. who knows), prakriti/purusha is the metaphysical pairing (what acts vs. what witnesses) — and verses 2-3 start collapsing them into one framework almost immediately.