tasv avatsit sva-srstasu
tena narayano nama
yad apah purusodbhavah
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
That Supreme Person is not impersonal and therefore is distinctively a nara, or person. Therefore the transcendental water created from the Supreme Nara is known as nara. And because He lies down on that water, He is known as Narayana.