One verse

Srimad Bhagavatam 10.50.9

10.50.9

एतदर्थोऽवतारोऽयं भूभारहरणाय मे । संरक्षणाय साधूनां कृतोऽन्येषां वधाय च ॥ ९ ॥

etad-artho ’vatāro ’yaṁ bhū-bhāra-haraṇāya me saṁrakṣaṇāya sādhūnāṁ kṛto ’nyeṣāṁ vadhāya ca

etat
for this
arthaḥ
purpose
avatāraḥ
descent
ayam
this
bhū
of the earth
bhāra
the burden
haraṇāya
for removing
me
by Me
saṁrakṣaṇāya
for the complete protection
sādhūnām
of the saintly
kṛtaḥ
done
anyeṣām
of others (the nonsaintly)
vadhāya
for killing
ca
and

This is the purpose of My present incarnation — to relieve the earth of its burden, protect the pious and kill the impious.