Mbh 12.307.3b

It is Prakriti that causes the overpresiding Purusha to thus assume diversity and revert back to unity. Prakriti also herself has the same indications. Only one fully conversant with the nature of the topics of enquiry knows that Prakriti also assumes the same kind of diversity and unity, for when Destruction comes she reverts into unity and when Creation flows she assumes diversity of form. The Soul makes Prakriti, which contains the principles of production or growth, to assume manifold forms. Prakriti is called Kshetra (or soul). Transcending the four and twenty topics or principles is the Soul which is great. It presides over that Prakriti or Kshetra. Hence, O great king, the foremost of Yatis say that the Soul is the Presider. Indeed, it has been heard by us that in consequence of the Soul's presiding over all Kshetras He is called the Presider. And because He knows that Unmanifest Kshetra, He is, therefore, also called Kshetrajna (Knower of Kshetra). And because also the Soul enters into Unmanifest Kshetra (viz., the body), therefore he is called Purusha. Kshetra is something quite different from Kshetrajna. Kshetra is Unmanifest. The Soul, which transcends the four and twenty principles, is called the Knower. Knowledge and the object known are different from each other. Knowledge, again, has been said to be Unmanifest, while the object of knowledge is the Soul which transcends the four and twenty principles. The Unmanifest is called Kshetra, Sattwa (understanding), and also Iswara (the supreme Lord), while Purusha, which is the twenty-fifth principle has nothing superior to it and is not a principle (for it transcends all principles and is only called a principle conventionally). This much O king, is an account of the Sankhya philosophy. The Sankhyas called the cause of the universe, and merging all the grosser principles into the Chit behold the Supreme Soul.