One verse

Srimad Bhagavatam 11.22.42

11.22.42

इन्द्रियायनसृष्‍ट्येदं त्रैविध्यं भाति वस्तुनि । बहिरन्तर्भिदाहेतुर्जनोऽसज्जनकृद् यथा ॥ ४२ ॥

indriyāyana-sṛṣṭyedaṁ trai-vidhyaṁ bhāti vastuni bahir-antar-bhidā-hetur jano ’saj-jana-kṛd yathā

indriya-ayana
by the resting place of the senses (the mind)
sṛṣṭyā
because of the creation (of identification with a new body)
idam
this
trai-vidhyam
threefold variety (of high, middle and low class)
bhāti
appears
vastuni
in the reality (the soul)
bahiḥ
external
antaḥ
and internal
bhidā
of the differences
hetuḥ
the cause
janaḥ
a person
asat-jana
of a bad person
kṛt
the progenitor
yathā
as

Because the mind, which is the resting place of the senses, has created the identification with a new body, the threefold material variety of high, middle and low class appears as if present within the reality of the soul. Thus the self creates external and internal duality, just as a man might give birth to a bad son.