Bhagavatapurana 3.28.21.p2

3.28.21.p2

yac-chauca-niḥsṛta-sarit-pravarodakena $ tīrthena mūrdhny adhikṛtena śivaḥ śivo 'bhūt &

22. He should for a long time contemplate the lotus-like feet of the Lord which drop the thunder-bolt upon (annihilate) the mountain of impurities in the mind of one that contemplates them; (He should contemplate) the feet from which flows the Great River formed by washing them, the hallowed waters of which Siva bore on his head and became Siva (highly blessed).