One verse

Srimad Bhagavatam 3.5.29

3.5.29

महत्तत्त्वाद्विकुर्वाणादहंतत्त्वं व्यजायत । कार्यकारणकर्त्रात्मा भूतेन्द्रियमनोमय: । वैकारिकस्तैजसश्च तामसश्चेत्यहं त्रिधा ॥ २९ ॥

mahat-tattvad vikurvanad aham-tattvam vyajayata karya-karana-kartratma bhutendriya-mano-mayah vaikarikas taijasas ca tamasas cety aham tridha

mahat
the great
tattvat
from the causal truth
vikurvanat
being transformed
aham
false ego
tattvam
material truth
vyajayata
became manifested
karya
effects
karana
cause
kartr
doer
atma
soul or source
bhuta
material ingredients
indriya
senses
manah-mayah
hovering on the mental plane
vaikarikah
the mode of goodness
taijasah
the mode of passion
ca
and
tamasah
the mode of ignorance
ca
and
iti
thus
aham
false ego
tridha
three kinds

Mahat-tattva, or the great causal truth, transforms into false ego, which is manifested in three phases—cause, effect and the doer. All such activities are on the mental plane and are based on the material elements, gross senses and mental speculation. The false ego is represented in three different modes—goodness, passion and ignorance.