That which is subject to modification (yad vikāri) — by whatever modification it is modified. And that which from which something proceeds and is set in motion (yat śca yat yat yato yāti pravartate) — he who is the originator. And that by which the field functions (yatś ca yad iti asmāt pravartate kṣetram iti vacanaṃ) — this denotes the field; and 'sa ca ya' indicates mere essential nature.