Bhagavad Gita Chapter 13, Verse 7

इच्छा द्वेषः सुखं दुःखं सङ्घातश्चेतना धृतिः | एतत्क्षेत्रं समासेन सविकारमुदाहृतम् ||

icchā dveṣaḥ sukhaṁ duḥkhaṁ saṅghātaś cetanā dhṛtiḥ etat kṣetraṁ samāsena sa-vikāram udāhṛtam

Desire, aversion, pleasure, pain, the aggregate (body), consciousness, and steadfastness—this field, with its modifications, has been briefly described.

Krishna completes the description of the field by including the psychological and emotional components: desire (icchā), aversion (dveṣa), pleasure (sukha), pain (duḥkha), the aggregate body (saṅghāta), consciousness (cetanā), and steadfastness (dhṛti). All of this—your desires, aversions, pleasures, pains, your body, your consciousness, your determination—is the field. Most people think they are their desires, their emotions, their experiences. But you're not. You're the knower who experiences desire, aversion, pleasure, pain. The field includes everything you can experience or identify with. The knower is what experiences it all. This complete description helps you recognize the full scope of the field, so you can distinguish it from the knower. The field has modifications—it changes constantly. But the knower remains constant.