SB 5.25.2

yasyedaṁ kṣiti-maṇḍalaṁ bhagavato ’nanta-mūrteḥ sahasra-śirasa ekasminn eva śīrṣaṇi dhriyamāṇaṁ siddhārtha iva lakṣyate.
Synonyms: 
yasya — of whom; idam — this; kṣiti-maṇḍalam — universe; bhagavataḥ — of the Supreme Personality of Godhead; ananta-mūrteḥ — in the form of Anantadeva; sahasra-śirasaḥ — who has thousands of hoods; ekasmin — on one; eva — only; śīrṣaṇi — hood; dhriyamāṇam — is being sustained; siddhārthaḥ iva — and like a white mustard seed; lakṣyate — is seen.
Translation: 
Śukadeva Gosvāmī continued: This great universe, situated on one of Lord Anantadeva’s thousands of hoods, appears just like a white mustard seed. It is infinitesimal compared to the hood of Lord Ananta.