SB 10.16.36
kasyanubhavo ’sya na deva vidmahe
tavanghri-renu-sparasadhikarah
yad-vañchaya srir lalanacarat tapo
vihaya kaman su-ciram dhrta-vrata
Translation:
O Lord, we do not know how the serpent Kaliya has attained this great opportunity of being touched by the dust of Your lotus feet. For this end, the goddess of fortune performed austerities for centuries, giving up all other desires and observing austere vows.