One verse

Srimad Bhagavatam 6.13.8-9

6.13.8-9

ब्रह्महा पितृहा गोघ्नो मातृहाचार्यहाघवान् । श्वाद: पुल्कसको वापि शुद्ध्येरन् यस्य कीर्तनात् ॥ ८ ॥ तमश्वमेधेन महामखेन श्रद्धान्वितोऽस्माभिरनुष्ठितेन । हत्वापि सब्रह्मचराचरं त्वं न लिप्यसे किं खलनिग्रहेण ॥ ९ ॥

brahma-ha pitr-ha go-ghno matr-hacarya-haghavan svadah pulkasako vapi suddhyeran yasya kirtanat tam asvamedhena maha-makhena sraddhanvito ’smabhir anusthitena hatvapi sabrahma-caracaram tvam na lipyase kim khala-nigrahena

brahma-ha
a person who has killed a brahmana
pitr-ha
a person who has killed his father
go-ghnah
a person who has killed a cow
matr-ha
a person who has killed his mother
acarya-ha
a person who has killed his spiritual master
agha-van
such a sinful person
sva-adah
a dog-eater
pulkasakah
a candala, one who is less than a sudra
va
or
api
even
suddhyeran
may be purified
yasya
of whom (Lord Narayana)
kirtanat
from chanting the holy name
tam
Him
asvamedhena
by the asvamedha sacrifice
maha-makhena
the topmost of all sacrifices
sraddha-anvitah
endowed with faith
asmabhih
by us
anusthitena
conducted or managed
hatva
killing
api
even
sa-brahma-cara-acaram
all the living entities, including the brahmanas
tvam
you
na
not
lipyase
are contaminated
kim
what then
khala-nigrahena
by killing one disturbing demon

One who has killed a brahmana, one who has killed a cow or one who has killed his father, mother or spiritual master can be immediately freed from all sinful reactions simply by chanting the holy name of Lord Narayana. Other sinful persons, such as dog-eaters and candalas, who are less than sudras, can also be freed in this way. But you are a devotee, and we shall help you by performing the great horse sacrifice. If you please Lord Narayana in that way, why should you be afraid? You will be freed even if you kill the entire universe, including the brahmanas, not to speak of killing a disturbing demon like Vrtrasura.