One verse

Srimad Bhagavatam 8.22.25

8.22.25

यदा कदाचिज्जीवात्मा संसरन् निजकर्मभि: । नानायोनिष्वनीशोऽयं पौरुषीं गतिमाव्रजेत् ॥ २५ ॥

yada kadacij jivatma samsaran nija-karmabhih nana-yonisv aniso ’yam paurusim gatim avrajet

yada
when
kadacit
sometimes
jiva-atma
the living entity
samsaran
rotating in the cycle of birth and death
nija-karmabhih
because of his own fruitive activities
nana-yonisu
in different species of life
anisah
not independent (completely under the control of material nature)
ayam
this living entity
paurusim gatim
the situation of being human
avrajet
wants to obtain.

While rotating in the cycle of birth and death again and again in different species because of his own fruitive activities, the dependent living entity, by good fortune, may happen to become a human being. This human birth is very rarely obtained.