dvāḥ-stheṣu paureṣv api śāyiteṣv atha
dvāraś ca sarvāḥ pihitā duratyayā
svayaṁ vyavaryanta yathā tamo raveḥ
vavarṣa parjanya upāṁśu-garjitaḥ
śeṣo ’nvagād vāri nivārayan phaṇaiḥ
Śeṣa-nāga is an expansion of the Supreme Personality of Godhead whose business is to serve the Lord with all necessary paraphernalia. When Vasudeva was carrying the child, Śeṣa-nāga came to serve the Lord and protect Him from the mild showers of rain.