The figure of speech, metaphor is used for easy explanation.
"Dharmakshetre Kurukshetre samavetaa yuyutsavah
Maamakaah paandavashchiav kim kurvat sanjaya"

The body is designed for action. Inaction is tantamount to heresy as the basic purpose of the creation is flouted. In the very first Shlok, bhagavadgitha declares that the action is the aim of this physical body and not inaction. The body is called, Kuru Kshetra. Kuru means doing, means action and Kshetra means arena. Kuru Kshetra, this physical body is the arena of action. Nobody can afford to be indolent. This body is inert (Jad). There must be something that guides this body. This guiding part is the intellect which determines what is good and what is bad. This discrimination is indeed the Dharm Kshetra.

Here Dhritraashtra is a blind king whose sons are outpouring sense inclinations towards sense objects. Dhritraashtra is indeed the blind mind. Sanjaya is the introspection. Every individual has introspection, the impartial witness of the happenings. Dhritraashtra is naturally sense inclined. His sons are outbound sense cravings. The rarefied higher levels of Dharm Kshetra are intellect. Intellect is the area of discrimination. There is a regular tussle between the forces of Pravritti which are streaming outwards towards the external world and the forces of Nivritti which direct the individual towards the supreme reality. This war is indeed the mental turmoil in every seeker. A completely ignorant person and a realized soul have no contradictions. The war is between the Pravritti forces and Nivritti forces of a seeker. The Pravritti forces are represented by the Kaurav while the Nivritti forces are represented by Paandav.

Every Shlok of Bhagavad Geetaa has a fire for all of us and it can outweigh all the self-help books that are published so far. A learned man asked the preacher of Bhagavad Geetaa to stop at the end of the first Shlok and exclaimed in a great joy that he has got the essence of Geetaa in the first Shlok itself and that is enough. The preacher asked, "What is that? The first Shlok is "Dharmakshetre kurukshetre samavetaa yuyutsavah, maamkaah paandavaishchaiva kim kurvat sanjaya." The learned man said, take the first two words of this Shlok and rearrange and you will get the whole gist. Dharmakshetre kurukshetre; You rearrange this as Kshetre Kshetre kuru Dharm meaning, Engage this body in Dharm.

The quintessence of first Shlok is a call to change our lifestyle from being spiritually inactive to robustly active. We have to train our mind to ask questions about our own self. Our mind is blind Dhritraashtra and our impartial witness is Sanjaya. We have to develop the habit of introspection every night before going to bed. We have to ask our impartial witness to report all the happenings of the day verbatim (Kurukshetra) . What were our sensory cravings of the day (Kaurav forces)? What were the inner discriminatory voices that stood up (Paandav forces) to oppose the sensory onslaught?. What a great practical suggestion in the very first Shlok