One verse

Srimad Bhagavatam 10.4.38

10.4.38

यथामयोऽङ्गे समुपेक्षितो नृभि- र्न शक्यते रूढपदश्चिकित्सितुम् । यथेन्द्रियग्राम उपेक्षितस्तथा रिपुर्महान् बद्धबलो न चाल्यते ॥ ३८ ॥

yathāmayo ’ṅge samupekṣito nṛbhir na śakyate rūḍha-padaś cikitsitum yathendriya-grāma upekṣitas tathā ripur mahān baddha-balo na cālyate

yathā
as
āmayaḥ
a disease
aṅge
in the body
samupekṣitaḥ
being neglected
nṛbhiḥ
by men
na
not
śakyate
is able
rūḍha-padaḥ
when it is acute
cikitsitum
to be treated
yathā
and as
indriya-grāmaḥ
the senses
upekṣitaḥ
not controlled in the beginning
tathā
similarly
ripuḥ mahān
a great enemy
baddha-balaḥ
if he becomes strong
na
not
cālyate
can be controlled

As a disease, if initially neglected, becomes acute and impossible to cure, or as the senses, if not controlled at first, are impossible to control later, an enemy, if neglected in the beginning, later becomes insurmountable.