Bhagavad Gita · 13.2

श्रीभगवानुवाचइदं शरीरं कौन्तेय क्षेत्रमित्यभिधीयते।एतद्यो वेत्ति तं प्राहुः क्षेत्रज्ञ इति तद्विदः॥

śhrī bhagavān uvācha idaṁ śharīraṁ kaunteya kṣhetram ity abhidhīyate etad yo vetti taṁ prāhuḥ kṣhetrajña iti tadvidaḥ

The Supreme Lord said: O son of Kunti, this body is called the field, and one who knows this body is called the knower of the field by the wise.

— Bhagavad Gita 13.2

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