1 Gita Sloka Every Day - Chapter 13 - Kshetra Kshetrajna Yoga - Sloka 3

The entire content of this mail is from Swami Adidevananda's translation of Ramanuja's  Gita  Bhashya and Swami Chidbhavananda's Bhagavad Gita, both published by Ramakrishna Mission

1 Gita Sloka  Every Day - Chapter 13 - Kshetra Kshetrajna Yoga - Sloka 3

Thiruppavai Pasuram 22

Tat kshetram yat cha yadrk cha yad vikari yatah cha yat I

Sah cha yah yad prabhavah cha tat samasena me shrunu II sloka 3

तत्  क्षेत्रम् यत् च यद्र्क च यद् विकारी यतः च यत् I

सः च यः यद् प्रभावः च तत् समासेन मे शृणु II श्लोक 3 

Hear briefly from me, what the kshetra is, what its properties are, what its modifications are,  whence is what; and who he is and what his powers are.

Nothing exists and nothing remains to be known outside the pale of the kshetra and kshetrajna. The vedas and vedanta philosophy  are all directed to the enquiry into these two ultimate realities. All the branches of knowledge that are so far revealed  and that are yet to  be revealed, that are conventionally divided into the sacred and secular - all of them are engaged in explaining either the  kshetra or  kshetrajna or both

The how of it is delineated in the following stanza