One verse

Srimad Bhagavatam 5.11.7

5.11.7

तावानयं व्यवहार: सदावि:क्षेत्रज्ञसाक्ष्यो भवति स्थूलसूक्ष्म: । तस्मान्मनो लिङ्गमदो वदन्तिगुणागुणत्वस्य परावरस्य ॥ ७ ॥

tavan ayam vyavaharah sadavih ksetrajna-saksyo bhavati sthula-suksmah tasman mano lingam ado vadanti gunagunatvasya paravarasya

tavan
until that time
ayam
this
vyavaharah
the artificial designations (being fat or skinny, or belonging to the demigods or human beings)
sada
always
avih
manifesting
ksetra-jna
of the living entity
saksyah
testimony
bhavati
is
sthula-suksmah
fat and skinny
tasmat
therefore
manah
the mind
lingam
the cause
adah
this
vadanti
they say
guna-agunatvasya
of being absorbed in material qualities or devoid of material qualities
para-avarasya
and of lower and higher conditions of life

The mind makes the living entity within this material world wander through different species of life, and thus the living entity experiences mundane affairs in different forms as a human being, demigod, fat person, skinny person and so forth. Learned scholars say that bodily appearance, bondage and liberation are caused by the mind.