The Field of Action
Kṣetra ('field,' 'ground') is the term used in Bhagavad Gītā chapter 13 for the body-mind complex that serves as the 'field' of experience for the soul. Kṛṣṇa declares: idam śarīraṃ... kṣetram ity abhidhīyate — 'This body is called the kṣetra (field).' The kṣetra includes the physical body, the sense organs, the mind (manas), the intellect (buddhi), and the ego-principle (ahaṅkāra) — everything that belongs to the material dimension of the person.
Kṣetra and Kṣetrajña
The kṣetra (field) is always paired with the kṣetrajña ('knower of the field' — the ātman). The ātman, being the conscious witness, is not the field but the knower of it. Confusing the kṣetra with the kṣetrajña — taking the body for the self — is the fundamental error (deha-ātma-bhrānti) that drives saṃsāra.
Rāmānuja's Interpretation
Rāmānuja interprets Bhagavad Gītā 13 in a Vishishtadvaita frame: the kṣetra is Brahman's body (as matter), the kṣetrajña (individual soul) is also Brahman's body (as consciousness), and the ultimate 'Knower of all fields' (sarva-kṣetreṣu... kṣetrajñaṃ viddhi mām) is Brahman as the inner self of all. This three-level interpretation places Brahman as the innermost consciousness within the soul within the body.
Sacred Sites as Kṣetras
The word kṣetra also means 'sacred place' or 'sacred field' — Divya Desams are called kṣetras because they are 'fields of merit' where devotion and liberation are cultivated. The dual meaning (body and sacred site) reflects the principle that the Lord's presence sanctifies wherever He dwells.