Skandapurana 5.8.111

5.8.111

yayā yāti drutaṃ pāpaṃ brahmahatyāsamudbhavam ..
spṛśyo bhavāmi sarveṣāṃ devānāṃ prapitāmaha .. 6.8.110 .
.. brahmovāca .. ..
tīrthayātrāṃ suraśreṣṭha tadarthaṃ kartumarhasi .
tayā vinā na te pāpaṃ nāśamāyāti kṛtsnaśaḥ .. 111 ..

By which the sin arising from the murder of a brahmin quickly departs,
[and] I may become touchable to all the gods, O great-grandfather.
Brahmā said:
For that purpose, O best of the gods, you ought to undertake a pilgrimage to sacred fords;
without it, your sin will not go to destruction entirely. 111