क्षेत्रं शरीरमित्याहुस्तदसौ वेत्त्यखण्डितम् ।सबाह्याभ्यन्तरं तेन क्षेत्रज्ञ इति कथ्यते
In plain words
The "field" (kṣetra), they say, is the body; and this knower knows it as an undivided whole, together with all that is outer and inner in it — and for this it is called kṣetrajña, the knower of the field.